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Slope engineering is primarily focused on landslides nowadays due to increasing number of its episodes. Most of the landslides occur on manmade slopes and it is actually the consequence of the uncertainties carried by different contributing factors. This study explores the causes of Highland Towers 1993 landslide based on reliability analysis technique and taking into account the role of human errors in the contribution of landslide. It is an established fact that the probability of failure derived from structural reliability analysis is conditional which does not incorporate human factors. The analysis considered in this study is based on Monte Carlo simulation by using the commercial slope/w software to evaluate the stability of the slope. The reason for selecting this software is that it combines both deterministic and probabilistic modules which provides more reliable results. These investigations are followed by fault tree analysis (FTA) to quantify the human error causes of failure by determining the chances of landslide governing with different events. The results of FTA show that the potential causes of this landslide are inadequate drainage, failure of rubble wall, and rail pile foundation which confirms that human errors have played a significant role in triggering the landslide. Therefore, this study suggests the use of human reliability analysis technique along with structural analysis to address the risks associated with the slopes.
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Landslide of Highland Towers 1993: a case study of Malaysia
Danish Kazmi
Sadaf Qasim
I. S. H. Harahap
Syed Baharom
Received: 1 February 2017 / Accepted: 1 June 2017
Springer International Publishing AG Switzerland 2017
Abstract Slope engineering is primarily focused on land-
slides nowadays due to increasing number of its episodes.
Most of the landslides occur on manmade slopes and it is
actually the consequence of the uncertainties carried by
different contributing factors. This study explores the
causes of Highland Towers 1993 landslide based on reli-
ability analysis technique and taking into account the role
of human errors in the contribution of landslide. It is an
established fact that the probability of failure derived from
structural reliability analysis is conditional which does not
incorporate human factors. The analysis considered in this
study is based on Monte Carlo simulation by using the
commercial slope/w software to evaluate the stability of the
slope. The reason for selecting this software is that it
combines both deterministic and probabilistic modules
which provides more reliable results. These investigations
are followed by fault tree analysis (FTA) to quantify the
human error causes of failure by determining the chances
of landslide governing with different events. The results of
FTA show that the potential causes of this landslide are
inadequate drainage, failure of rubble wall, and rail pile
foundation which confirms that human errors have played a
significant role in triggering the landslide. Therefore, this
study suggests the use of human reliability analysis tech-
nique along with structural analysis to address the risks
associated with the slopes.
Keywords Landslides Highland Towers 1993
Reliability analysis Monte Carlo simulation Slope/w
software Fault tree analysis
In 1993, the collapse of Highland Towers in Kuala Lum-
pur, Malaysia resulted in 48 deaths. According to the report
of Maverick [1], one of the major causes of landslide was
improper soil testing. The peripheral conditions of site
resulted in undermining. The failure of retaining walls
under heavy rains was a contributing factor, causing a
landslide that led to the building’s collapse. There were
two types of design errors, improper soil’s bearing test and
pre-construction site visit at pre-design phase and the
failure to identify the peripheral condition at site, together
with the failure to design an inadequate retaining wall to
contain the site and the building that stood on it [2]
(Fig. 1).
According to Aini and Fakhru’l-Razi [4], the collapse of
Block 1 of Highland Towers Condominium could also be
avoided if the authority and the owner investigated inci-
dences of flooding and mudflow prior to the disaster.
Heavy rain on December 11, 1993 had caused retrogressive
landslides behind Block 1, which consequently induced the
instability of the rail pile foundation, which was not
designed for lateral loading. Inadequate provision of drai-
nage and lack of maintenance of drains aggravated the
&Danish Kazmi
Sadaf Qasim
I. S. H. Harahap
Syed Baharom
Department of Civil Engineering, NED University of
Engineering and Technology, Karachi 75270, Pakistan
Department of Civil and Environmental Engineering,
Universiti Teknologi Petronas, 32610 Perak, Malaysia
Innov. Infrastruct. Solut. (2017) 2:21
DOI 10.1007/s41062-017-0069-4
friable nature of the slope materials, which increased sur-
face runoff and infiltration rate that finally triggered a
series of landslides (Figs. 2,3).
The reason for studying the background of Highland
Towers 1993 landslide is that it resulted in significant
compensatory and non-compensatory losses coupled with
the fact that many other landslides also took place in the
same vicinity.
A number of fatal landslides have been reported in Ulu
Klang starting with the tragedy of Highland Tower collapse
in 1993, followed by a landslide at Taman Hillview on
November 20, 2002. Subsequently, landslides were repor-
ted at Taman Hamorni, Taman Zoo View KampungPasir
on May 31, 2006 and the most recent was at Taman Bukit
Mewah, the December 6, 2008. These landslides have
resulted in casualties and loss of lives, notwithstanding
displacements of residents and extensive damages to
properties [6] (Table 1).
Ulu Klang region in Malaysia is very susceptible to
landslides. This area is located in Kuala Lumpur, the
capital city of Malaysia between 30902500 and 31304500
East latitude and 1014401300 and 1014705100 North longi-
tudes. Urban development has brought many problems to
this region including numerous landslide and mudflow
events. The Ulu Kelang area has suffered several fatal
landslides caused by rainfall events. There were 28 major
landslide events identified as rainfall-induced landslides
since 1984. The Highland Towers slide stands as one of the
most significant tragedies involving 48 deaths due to tower
collapse after several days of rainfall in 1993 [7].
According to Malaysian meteorological department
(MMD), the temperature of the Ulu Klang area is usually
between 29 and 32 C with a mean relative humidity of
65–70%. The average annual temperature is about 25 C.
April and June are the highest temperature months, while
the relative humidity is lowest in June, July, and September
[7] (Fig. 4).
Slope engineering demands full concentration at the
moment due to increasing number of landslides. Most of
the landslide failures are related to manmade slopes and
this requires immediate attention to address the problem. It
is in actual the problems of the deficit design, faulty and
poor construction or being ignorant from the maintenance
[9]. In one of the sectoral reports of Malaysia, among 49
major cases of landslides, 88 percent are attributed to
manmade slopes [10]. To date this fact is not truly recog-
nized that uncertainties related to human factors needs to
be tackled methodologically. In fact, researchers believe
that human uncertainties prevailing in the construction
industry are similar to the uncertainties governing with soil
properties and the selected models. Schu
¨ttrumpf et al. [11]
also recognized the role of human uncertainties by giving it
the name of human factors while discussing the design of
Fig. 1 Highland Towers collapse [3]
Fig. 2 Original cross-section through block 1 [5]
Fig. 3 Sequence of retrogressive landslides [5]
21 Page 2 of 9 Innov. Infrastruct. Solut. (2017) 2:21
coastal structures. Essentially, human reliability analysis
weighs up those uncertainties that stems from human fac-
tors and are necessary to be addressed for ensuring the
structural integrity and safety.
A reliability analysis aims to evaluate the probability
that capacity exceeds with respect to demand. Reliability
(R) can be expressed indirectly through probability of
failure (P
). Mathematical definition for probability of
failure is expressed as follows:
As reported by Duncan [12], the reliability calculations
support to work out the combined effects of uncertainties.
Reliability analysis also distinguishes between those con-
ditions where uncertainties are varying. Safety factor
approach is apparently logical as it is based on experience
but the only problem is that it does not have the ability to
counter uncertainties.
Table 1 Major landslides in
Ulu Klang area from year 1993
to 2008 [6]
No Date Location of slope failure
1 11.12.1993 Highland Tower
2 14.05.1999 Bukit Antarabangsa, Ampang-Ulu Klang
3 15.05.1999 Athanaeum Towers, Ulu Klang
4 05.10.2000 Bukit Antarabangsa
5 29.10.2001 Taman Zoo View, Ulu Klang
6 08.11.2001 Taman Zoo View, Ulu Klang
7 20.11.2002 Taman Hill View
8 02.11.2003 Oakleaf Park Condominiums in Bukit Antarabangsa
9 07.11.2003 Jalan Bukit Mulia, Bukit Antarabangsa, Ulu Klang
10 31.01.2005 JalanTebrau in DataranUkay, Ulu Klang
11 01.02.2005 JalanTebrau, DataranUkay, Ulu Klang
12 31.03.2006 Taman Zoo View - Kg Pasir, Ulu Klang
13 06.12.2008 Taman bukit Mewah, Bukit Antarabangsa, Ulu Klang
Fig. 4 Location of Ulu Klang [8]
Innov. Infrastruct. Solut. (2017) 2:21 Page 3 of 9 21
The reason for considering reliability analysis is that
the conventional slope practices are unable to quantify
the risks as they only runs with judgment and expe-
riences. These traditional practices have no provision of
attending the uncertainties. Thus, reliability index is a
more logical measure of stability rather than factor of
safety. Santamarina et al. [13] ascertained the Table 2.
These criteria’s combine together with standard levels
of probability of failure with various design conditions.
Dai et al. [14] discussed about the probability of failure for
site-specific slopes. In actual, probability of failure is refer-
ring to the probability of the safety factor having value less
than 1. The performance function G XðÞis the main function
of the slopes which differentiates between the safety and the
failure. If G XðÞ[0 failure will not take place. The G XðÞ\0
shows that safety level is alarming which means most
probably it will fail. The performance function G XðÞ¼0isa
limit state boundary. It separates the two states. Once the
performance function is established by taking all input
variables involved in stability analysis, probability of failure
can be drawn by statistical tools.
Mathematically, the performance function is defined as
where safety factor, resistance, and load are denoted by
FxðÞ,RxðÞ, and SxðÞ, respectively.
Quantification of uncertainties needs reliability approa-
ches and reliability analysis tools. It is a misperception that
an ample amount of data and thorough probabilistic
knowledge is required for reliability theory. Reliability
theory can be applied on nearly the same data and judg-
ments that are used in conventional analysis. In reliability
analysis, probability of failure is represented by (P
) and
reliability index by (b).
Objective of the study
The objectives of the study are given below.
To explore the causes of Highland Towers 1993
To evaluate the role of human uncertainties in the
landslide by applying fault tree analysis (FTA)
Method and area of study
The Highland Towers collapse was an apartment building
collapse that occurred on December 11, 1993 in Taman
Hillview, Ulu Klang, Selangor, Malaysia. The collapse of
Block 1 of the apartments caused the deaths of 48 people
and led to the complete evacuation of the remaining two
blocks due to safety concerns. In 1991, a new housing
development project, known as Bukit Antarabangsa
Development Project, commenced construction on the
hilltop located behind the Highland Towers. The hill was
cleared of trees and other land-covering plants, exposing
the soil to land erosion that is the leading factor of causing
landslides [15].
This study explores the catastrophic landslide of High-
land Towers 1993 to study the causes which triggered the
failure. For investigation, probabilistic analysis is consid-
ered based on Monte Carlo simulation using the commer-
cial slope/w software to evaluate the stability of the slope.
Slope/w provides deterministic and probabilistic analysis
in one unit. The critical slip surface is acquired by deter-
ministic analysis, whereas the probabilistic analysis is
performed on the particular critical slip surface. These
investigations are followed by fault tree analysis (FTA)
which is a logical and diagrammatic method to evaluate the
probability of an incident resulting from sequences and
combinations of failure events. The FTA capitalizes on
logics and Boolean algebra to determine events that are
responsible for an undesired incident.
The required parametric and geometrical information
used in the application of reliability analysis methods is
established through previous studies. Geometrical config-
uration of the slope along with type and shear strength
properties of the soil are given below [5].
The slope height of Highland Tower 1993 is around
48 m as worked out through reduced levels.
Gradient of the Highland Tower 1993 is estimated
through working hill slope, ranges from 20to 30.
Soil properties from undamaged mass of Highland
Tower 1993 slope, effective cohesion is found to be in a
Table 2 Slope conditions and
failure probabilities [13]Conditions Probability of failures
Temporary structures with low repair cost 0.1
Existing large cut on interstate highway 0.01
Acceptable in most cases EXCEPT lives may be lost 0.001
Acceptable for all slopes 0.0001
21 Page 4 of 9 Innov. Infrastruct. Solut. (2017) 2:21
range from 4 kPa to 6 kPa and the friction angle is in
the range of 33–41 .
Bulk unit weight is 19 kN/m
Dry unit weight is 16.5 kN/m
Pore water pressure ratio (Ru) is applied as 0.1–0.4.
Strategy for probabilistic analysis
This study considers the analysis using slope/w software
which is a commanding slope analysis program. Using
limit equilibrium, it has the skill to analyze diverse soil
types, composite stratigraphic and slip surface geometry,
and uneven pore-water pressure conditions using a large
assortment of soil models. Analysis can be performed by
deterministic or probabilistic input parameters. It can
execute probabilistic slope stability analysis, taking into
account the variability allied with the input parameters. A
probabilistic analysis agrees to statistically calculate the
probability of failure of a slope via Monte Carlo method.
The results from all Monte Carlo attempts can be used to
figure out the probability of failure, factor of safety,
probability density, and distribution functions.
The parameters of soil obtained from literature have the
ability to carry out deterministic analysis. Probabilistic
analysis needs some additional statistical parameters of
unit weight, cohesion, and friction. Statistics like mean,
standard deviation, and coefficient of variation are actually
used to carry out probabilistic analysis and can be acquired
from previous literature in case of lack of data. For this
reason, six sigma (6r) method is taken into account. In (6r)
tool, range of the focused parameter is taken and divided
by 6. The output of standard deviation comes from this
sequence. Mathematically it can be defined as follows:
Standard deviation ¼Range
Random variables are generated according to already
calculated basic statistical parameters like mean, coeffi-
cient of variance, and type of distribution. These generated
random variables are joined together to form a limit state
function ‘G’ (on the basis of already determined limit state
function). Taking the definition of failure G\0, the
number of failing runs will count. Large numbers of iter-
ations are involved to approximate the probability of cer-
tain outcomes by using random variables. Mathematically,
it can be expressed as follows:
Pf¼number of trials failed
total number of trials :ð5Þ
In terms of the classes for probability, the below
table represents the corresponding intensity of failure
(Table 3).
Monte Carlo simulation is a powerful tool for slope
stability and risk analysis. This method consists of four
basic steps which include the following:
1. Selecting a random worth for each input variable
according to dispensed probability density function.
2. Calculating factor of safety by using a proper deter-
ministic slope stability analysis method based on
selected values in step 1.
3. Repeating step 1 and 2 for as many times as necessary.
4. Determining distribution function of factors of safety
and probability of failure.
According to Monte Carlo simulation method, a random
value has been selected for each input parameter based on
the assigned probability density function. Theoretically, the
more Monte Carlo trials make the solution more accurate
but the number of required Monte Carlo trials is dependent
on the level of confidence in the solution and the amount of
variables being considered.
In reliability analysis, probability of failure (P
) and
reliability index (b) are two major parameters for mea-
suring the safety. The reliability index is defined as the
distance between mean safety margin and the failure limit.
Mathematically, reliability index can be expressed as
where E(FS) and r(FS) are average and standard devia-
tion of safety factors, respectively.
The relation between reliability index and probability of
failure is given below (Table 4).
It is a fact that safety factor approach is conservative and
not sufficient for ultimate design because the results
obtained from this approach are conditional as it lacks the
impact of human errors. This fact is also supported by the
studies of Duncan [12] and Phoon [18] which establishes
that the collapse of Highland Towers 1993 requires further
investigation by considering the role of human errors in the
failure. For this reason, this study applies the technique of
fault trees analysis (FTA) to quantify the human error
Table 3 Classes for probability [16]
Qualitative evaluation Quantitative evaluation Value
Certain Every time 1.0
Very high One in a ten 10
High One in a hundred 10
Moderate One in a thousand 10
Low One in ten thousand 10
Very low One in a hundred thousand 10
Extremely low One in a million 10
Practically zero One in ten million 10
Innov. Infrastruct. Solut. (2017) 2:21 Page 5 of 9 21
causes of Highland Towers 1993 which are mentioned in
the findings of the previous studies of MPAJ [19], Jaapar
[20] and Sew [21] and Aun [22].
The fault tree is developed to analyze the collapse of
Highland Towers 1993 and is relevant to the following
scenarios of human errors as discussed by MPAJ [19], Sew
[21] and Aun [22].
1. The agreed drainage system on the hill slope following
Highland Towers 1993 has never been done.
2. Slope and rubble walls behind and in front of Block 1
were improperly designed having factor of safety less
than 1.
3. The instability of rail pile foundation.
The purpose of using FTA is to estimate the likelihood
scenario of an accident. Its quantification needs probabili-
ties of the basic events located at the last level of the fault
tree. The assigned probabilities of the basic events have to
be estimated through information reported in the literature
or by analyst’s experience. If available it is best suitable to
use activity specific data, which usually arises from pre-
ventive maintenance records or from review of previous
incident literature. The concept of subjective probabilities
is commonly applied in geotechnical engineering as it
reflects the subject’s opinion without any stringent calcu-
lations. It is also mentioned by Silva [23] that geotechnical
engineers frequently come up to the determination of
failure probabilities. The previous studies of Christian [24]
and Stewart [25] show that subjective probabilities, such as
quantified expert judgment, have been accepted for decades
by practitioners and academics alike.
Qasim and Harahap [26] performed the reliability assess-
ment of Highland Towers 1993 using slope/w program.
Safety level of the slope has been measured both deter-
ministically and probabilistically. It has been found that the
maximum value of concluded safety factor is 1.502 even
from the most rigorous method of Morgenstern-Price. The
safety factor values from all four methods are given below
(Table 5).
The search of the position and radius of critical slip
surface is the trickiest part of the slope stability analysis. It
is not only depending on the geometry of the slope being
analyzed but also on the strength parameters. In deter-
ministic analysis of slope, mean values of input parameter
are always used and this will acquiesce on a particular
failure surface. In slope/w, the use of a probabilistic anal-
ysis will not impinge on the deterministic solution. Slope/w
calculates the factor of safety of all slip surfaces first and
determines the critical slip surface as if no probabilistic
analysis is elected. The probabilistic investigation is than
performed on the deterministic critical slip surface [26]
(Table 6).
When probabilistic analysis is performed, reliability
index for three different cases of soil parameters has been
taken. An inherent probabilistic tool of Monte Carlo sim-
ulation of slope/w software is utilized by having 1000,
2000, and 3000 trials. As the number of trials increases, the
results become more refined [26] (Table 7).
From the above results, the reliability index on 3000
auditions for Highland Towers 1993 found to be 1.07
which is alarmingly low; however, the safety factor in this
case is 1.5. These results indicate that there is no correla-
tion between factor of safety and probability of failure.
Lacasse and Nadim [27] have already highlighted this point
while investigating the pile design. Another important
aspect is that the probability of failure derived in this case
is human error free; it only reflects soil variability or model
uncertainties. Therefore, this study performs the fault tree
analysis (FTA) of the Highland Towers 1993 collapse to
investigate the neglected part of human errors.
The technique of FTA is used to determine the chances
of failure governing with different events. The probabilities
of basic events have been taken by the combination of
analyst’s opinion and the previous sources. The qualitative
construction of the fault tree replicates the relation among
the events. The first step in quantifying a fault tree is to
allocate preliminary probabilities to the basic events. This
step is performed by obtaining information from the
Table 4 Relationship between reliability index and probability of
failure [17]
index (b)
Probability of
failure (P
High 5 0.0000003
Good 4 0.00003
Above average 3 0.001
Below average 2.5 0.006
Poor 2 0.023
Unsatisfactory 1.5 0.07
Hazardous 1 0.16
Table 5 Mean safety factor values [26]
Methods Moment Force
Ordinary 1.425 –
Bishop 1.499 –
Jambu – 1.403
Morgenstern price 1.502 1.503
21 Page 6 of 9 Innov. Infrastruct. Solut. (2017) 2:21
concerned people in the industry to get expert opinion for
the analysis.
This study has followed the same strategy of FTA to
quantify the instability issues of Highland Towers 1993 by
acquiring the subjective probabilities of events through
leading consultants and officials of local bodies of
Malaysian region. Undoubtedly, Highland Towers 1993
collapse took place nearly after 15 years of its completion
but the factors that contributed to its failure are quantified
in this paper using FTA approach (Fig. 5).
The probability of failure of top event ‘‘Instability issues of
Highland Towers’’ is found to be 10
which reflects very
high level of risk according to established criteria of
probability of occurrence as mentioned by Kazmi et al.
[28]. The basic events which potentially contributed to
failure are inadequate drainage, failure of a rubble wall,
and rail pile foundation coupled with movement of soil. All
these factors show clear signs of human errors which
committed either intentionally or unintentionally. Accord-
ing to the study of Maniam [29], the implemented drainage
system in the vision of all experts of hydrology was totally
inadequate. Firstly, most of the drains were earth drains
that can be easily worn. Secondly, water can penetrate into
the soil of these earth drains at a superior rate as compared
to concrete. Along with, the flow pattern of these drains
was adverse. It does not have natural flow towards down-
hill and it had a number of U-turns, one of which even
flows in the same direction where it originated. Further, the
drains were deficient to lodge the sum of runoff from the
slope. Lastly, the drains were in an area where maintenance
must be on high priority due to thick vegetation cover.
One basic event of ‘‘rainfall exceeds’’ is also considered
during the performance of analysis. The probability of
failure due to this basic event is found to be moderate and
is equal to 10
while the event of inadequate drainage has
a value of 10
. It shows that water coupled with poor
drainage system are the prime contributors of the collapse
of the slope.
It is also essential to check the figures of cumulative
rainfall in the area of slope failure. It has been recorded that
the cumulative rainfall on the day of this disastrous event
was about 900 mm. The yearly rainfall for the year 1993
was 2604 mm. Thus, the cumulative rainfall from
September to December 11, 1993 is reported to be 35% of
the annual rainfall. The intensity of rainfall was severe in
the month of December prior to the day when the slope and
the Block 1 Tower collapsed. The seepage flow would have
played a part in the collapse of the slope since water
emerging from the rubble wall at the slope toe can cause
loss of support as the material collapsed locally leading to
the rotational retrogressive slope failure [22].
Jabatan Kerja Raya [30] reported that along with the
triggering factor of rainfall, inadequate factor of safety is
also one of the factors responsible for the failure. It
describes that factor of safety is basically not invariant in
nature but with the passage of time due to influence of rise
in ground water table/pore water pressure it variates and
lowers down. In that situation, the selection of safety factor
is based on taking all the relevant factors into consideration
In connection to slope failures and building collapse, the
human error uncertainties are dominantly prevailing in
design, construction, and maintenance phases but it has not
been fully recognized yet. In structural engineering, some
trials have been made to lower down the impacts of human
errors by proposing some models as discussed by Haan
[31] and Yousef [32]. Previous literature and studies also
confirm that human errors are directly and indirectly cou-
pled with geotechnical failures including the studies of
Jaapar [20], Minato [33], Kaliba [34], Sweis [35], Gue
[36], Rasip [37], and Samah [38]. It is also reported that
frequencies, consequences, and circumstances surrounding
human error occurrence should be understood before ana-
lyzing it [39].
The decision for the stability and longevity of slope is
taken mostly on the basis of safety factor value; however,
this has proved to be a distorted way of slope stability
analysis when human uncertainties are completely
neglected. Therefore, it is necessary that human uncer-
tainties must be evaluated in the slope construction along
with the technical aspects for minimizing the chances of
Table 6 Three different cases of soil parameters [26]
Standard deviation Case I Case II Case III
Unit weight 1 1 1
Cohesion 1 2 1
Friction 2 2 1
Table 7 Probabilistic results of case I, case II, and case III [26]
Trials Output quantities Case I Case II Case III
1000 Reliability index 1.03 1.13 1.10
Probability of failure (%) 12.12 12.88 13.45
2000 Reliability index 1.01 1.04 1.09
Probability of failure (%) 11.98 11.99 12.14
3000 Reliability index 1.05 1.07 1.01
Probability of failure (%) 10.98 11.12 11.18
Innov. Infrastruct. Solut. (2017) 2:21 Page 7 of 9 21
failure to ensure that the construction is performed as per
the specifications.
The role of human uncertainties in the construction is
gradually being recognized as one of the pivotal causes of
failure in civil engineering; hence, there is a need to
address these uncertainties by formulating various stan-
dards to deal with them accordingly. In case of Highland
Towers 1993, the contribution of human errors is found to
be dominant in triggering the landslide, and the potential
causes of failure include inadequate drainage, failure of
rubble wall, and rail pile foundation. It is now being real-
ized that reliability of the structure is not only technology
dependent but the quality of design, construction, and
maintenance must meet the specifications. This study
concludes that it is recommended to perform human reli-
ability analysis in slope construction to reduce the chances
of errors holistically. The findings also confirm that whe-
ther the safety factor of the slope is high or low, there is
always a possibility of instability if the probability of
failure due to human uncertainties is not tackled in a log-
ical manner.
Instability Issues of
Highland Tower
Movement of soil
Failure of a Rubble
Factor of safety <1
Faulty soil
10-6 Insufficient design
not considered
runoff due to
clearing of
diversion of water
drainage but
Complexity of
East stream was
diverted by pipe
Design flood
Not knowing
Mostly are earth
Drains are not
infiltration at
greater rate
Easily eroded
Staggered flow
Number of U-turns
are introduced
Not flows
Lack of
Insufficient to
run off
Third party
Failure of rail pile
Bucking and
shearing of rail
Accumulation of
fallen debris
only for
vertical loads
Fig. 5 Fault Tree of Highland Towers 1993 Landslide
21 Page 8 of 9 Innov. Infrastruct. Solut. (2017) 2:21
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... Despite the decline of the forested areas in the hilly Cameron Highlands, the anthropogenic land-use area increased from 1947 to 2016 in Cameron Highlands (Razali et al. 2018). Following Razali et al. (2018)'s statement that this situation persisted in other highlands in Malaysia, landslides are common occurrences on hilly areas in Malaysia, especially when manmade slopes and heavily populated areas are involved (JKR 2009;Lee et al. 2014;Kazmi et al. 2017). The most well-known case is possibly the landslide of the Highland Towers in 1993 with a death toll of 48, although it is not the case that has claimed most lives (JKR 2009). ...
Slope erosion and shallow failures occur in developed areas in Malaysia as a result of the natural vegetation removal, resulting in soil disturbance and greater exposure of bare ground. The use of bioengineering techniques through vegetation is a preferred solution to these problems by providing cover from rainfall and reinforcing the soil through root systems. Considering the potential of bioengineering in slope management, the current study aims to (i) review slope bioengineering techniques that uses vegetation to stabilise slope in Malaysia and (ii) highlight research gaps. Findings were discussed from 17 original studies published between 2000 and 2020, which were selected from the output of four databases (Scopus, Web of Science, Science Direct, and Google Scholar), several grey literature works, and local scientific publications. The studies on bioengineering using vegetation recorded that several slope species with superior performance in terms of beneficial traits, such as root length density and transpiration rate, were more prominent in Melastoma malabathricum and Leucaena leucocephala. Moreover, previous studies identified biomaterials that protected slopes, including empty fruit bunch and geotextiles, despite the currently critical limitations in the applicability of these techniques. This study highlighted the research gaps that may lead to the progress of the bioengineering techniques, such as beneficial traits and techniques, the exploration of mix-culture systems, and the utilisation of modelling techniques. This review serves as a structured and current overview of bioengineering knowledge for shallow slope instability and erosion management in Malaysia.
... When a ground is weakened due to poor drainage, the overall structure may crack, lean or fail. Kazmi et al (2017) conducted a probabilistic analysis and discovered that poor drainage was one of the major reasons why Highland Towers failed and collapsed killing 48 people. The causes of project defects vary, but they can be divided into three categories: design-related, maintenance-related and workmanship-related. ...
... When a ground is weakened due to poor drainage, the overall structure may crack, lean or fail. Kazmi et al (2017) conducted a probabilistic analysis and discovered that poor drainage was one of the major reasons why Highland Towers failed and collapsed killing 48 people. The causes of project defects vary, but they can be divided into three categories: design-related, maintenance-related and workmanship-related. ...
Conference Paper
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Poor workmanship and its links to ethical actions are widespread in the building industry. Construction players, including contractors and designers, are considered exposed to infringements of the law and liable for damages. The purpose of this paper is to provide a better awareness of ethical problems while building an open drainage system and its link to legal obligations. In combination with unstructured interviews and analyses of documents, the data have been obtained largely via naturalistic observation. The absence of attention to ethical practices has been proven to have harmful effects. Drainage failures were caused by missing elements (such as concrete bases and rubble packs) and by faulty construction of the drainage system, which complicates the financial situation and the contractor's time during construction. The acts of the contractor relate to fraud and negligence. The research reveals concepts of ethical blindness and unethical pro-organisation for more empirical research in future. In addition, increased emphasis on the Fraud Triangle and teleology might produce informative conclusions that are relevant to the attention and conduct of many parties. A proper construction of the drainage system is essential to avoid financial or legal after-effects.
... Since 1993, many landslides happened in Ulu Klang such as the collapse of Highland Towers which caused 48 deaths in 1993 [9], a landslide at Taman Hillview in 2002, landslides at Taman Hamorni, Taman Zoo View, Kampung Pasir in 2006 and the most recent was at Taman Bukit Mewah in 2008 [1, 10,11,12]. These tragedies have claimed lives and economic losses [1]. ...
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This paper aims to determine potential spaces for sustainable future development at Hutan Simpan Ampang, Ulu Klang, Malaysia. The site is highly valuable due to strategic location and high availability of spaces. However, due to several landslide incidents happened in Ulu Klang over the past decades, the site is categorised as a landslide-prone area. Therefore, Potential Surface Analysis (PSA) is conducted to determine the potential areas within the site that are safe and suitable for future development. All the factors were processed in Geographic Information System (GIS) through the overlay mapping technique, combining spatial and attribute data to obtain the suitability map. The result found that the majority coverage of the site is not suitable for any future development. There are only a few coverage areas that are suitable for small scale development. However, a combination of the very high suitability area and the high suitability area expanded the opportunity for sustainable future development.
... Other factors that can cause landslide are the effects of human activity and such as development activities carried out on the slopes and the uncontrolled cutting down of forest trees. According to Danish K. et. al. (2017), landslide that occurred in Highland Tower. Highland Tower, which is located in Taman Hillview, Hulu Klang, Selangor and built in December 1993, has received attention as the worst landslide ever to occur in Malaysia. Due to the impact of the landslide, many residents in the area lost their homes, property and also life. Therefore, to r ...
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In Malaysia, issues related to disaster management are always given attention in society and by the responsible parties. However, in general, citizen do not think of the consequential impact of disaster due to less of knowledge regarding the early phase in disaster management. Therefore, citizen in those areas will be more vulnerable to landslide as the citizen face difficulties in identifying specific areas with the tendency of landslides. This paper presents a geospatial metamodel approach for non-structural mitigation of landslide using data from airborne LiDAR and aerial photograph. Disaster management metamodel with geospatial element combines activity for managing disaster along with geospatial database that makes it handy for appreciating the metamodel. On the other hand, the digital terrain model (DTM) from LiDAR and aerial photograph is required to produce landslide inventory mapping. The case study area is located in Kundasang, Sabah, where landslides occur frequently. In order to get better visual in identifying landslides in the study area, three types of data are required to carry out image interpretation. The three types of data are hillshade, topographic openness and colour composite. The result of the landslide inventory map shows that there are five types of landslide, which is debris flow, debris fall, mud flow, deep-seated landslide and shallow landslide. Finally, the result of landslide inventory map will be integrated into the developed metamodel for presentation to the users. This landslide inventory map is used as a non-structural mitigation step in one of disaster management phases that is suitable to prepare and use in mitigating the landslide hazard impact.
... Several attempts have been made to estimate the degree of landslide susceptibility and provided some procedures for landslide prediction modeling by GIS, remote sensing, statistical analyzes, fuzzy logic, support vector machines and artificial neural network [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29]. Wu and Chen [30], assessing the model for landslide susceptibility in central Taiwan using the analytical hierarchy process (AHP) method. ...
In this article, the occurred landslide on the 27th kilometer of Kojour pathway, in the west of the Gat-e Kash village was surveyed and studied using geological maps, aerial photography and satellite images of the region. According to field investigations, this landslide is a transitional slide that occurred on Cretaceous marl successions near the Khachak over thrust fault and the Zanou’s river. Seven factors including lithology, topography, distance from fault, climate, land use, hydrology and hydrogeology and engineering geological conditions of the sliding mass were recognized and analyzed as effective parameters in the landslide. Based on engineering geological studies, the soil of the landslide is laid in SM-SC classes of the Unified Soil Classification System and has low swelling potential. The obtained safety factor by limit equilibrium stability analyses method indicated that the slope is stable in the present condition, but by changing in effective factors it may take place to unstable conditions again. The results of regression analyses showed the safety factor of the landslide is more controlled by specific gravity and degree of geomaterial saturation. During the field investigation, some sections with high potential of sliding were recognized; therefore, the most effective method including vertical and horizontal drainage and Gabion wall were offered for stabilization of the slope. Environmental assessments of the landslide were analyzed by the clustering technique, that negative impact was seen on soil erosion, surface and ground water quality, agriculture, road and communication.
... The technique of fault tree analysis (FTA) is fundamentally based on the subjective probabilities which are determined on the basis of respondents' judgment according to their experience and knowledge. The purpose of using FTA is to estimate the likelihood scenario of an accident [8]. According to Silva et al., 2008 [9], geotechnical engineers frequently encounter the challenge of determining the failure probabilities. ...
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Bukit Antarabangsa 2008 is considered as a deep-seated landslide which occurred in the landslide-prone area of Ulu Klang, Malaysia. The precipitation data obtained from previous studies show that there were comparatively less rainfalls immediately before the landslide which suggests that other potential triggers must be analyzed. This study analyses the causes of Bukit Antarabangsa 2008 landslide by performing fault tree analysis (FTA) which is a logical and diagrammatic method to evaluate the probability of an accident resulting from sequences and combinations of faults. The FTA is performed on four potential landslide contributors of improper shear strength parameters, flawed development plan, erroneous drainage planning & design and, ineffective slope strengthening works in order to determine the causes of the landslide. The analysis shows that the causes of Bukit Antarabangsa 2008 landslide potentially include ineffective slope strengthening works related to monitoring and maintenance which is followed by improper development plan having a probability of failure of 0.194 and 0.15 respectively. These causes actually correlate with the human errors which are often neglected during the slope construction and required to be addressed to increase the safety of the slopes.
... In this incident, the contribution of human error was found to be dominant in triggering the landslide. Other potential causes of failure included inadequacy of drainage, failure of rubble wall and rail pile foundation [22]. Later, on 6 December 2008, the study area experienced another landslide disaster only 1.4 km from the Highland Tower site, and the area was classified as having a high-risk potential for landslides [17]. ...
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Previous researchers have observed that imprecise design, flawed construction and non-maintenance of slopes are major contributors to Malaysian landslides. The prominent landslide of Bukit Antarabangsa in 2008 once again alarmed the Malaysian construction industry and prompted a review of their practices and standards. This study investigates the causes of the Bukit Antarabangsa landslide by analyzing a pipe burst event, which according to previous studies triggered the landslide. The technique of fault tree analysis (FTA) is applied to trace factors contributing to the pipe burst. The events and their subjective probability for the FTA have been ascertained by experts in the Malaysian construction industry through survey research using a snowball sampling technique. Subjective probability derived for FTA indicates that high acidity levels in the water, improper design and a temporary extra surcharge load were more likely to be causal factors than other potential triggers. The events that are found to have the highest subjective probability in causing the pipe burst correlate with human errors which occur either as a result of negligence or as a result of several types of uncertainties. In this context, this study suggests a theoretical framework to address human errors and to mitigate the chances of slope failure.
The morphometric assessment has proved to be effective in recognizing and analyzing the neotectonic signatures governing a particular drainage basin. Studies on morphometric properties involving the linear, areal, and relief aspects are vital as it aids in evaluating the hydrological response and prioritization of watersheds. The present research attempts to investigate and compare the morphometric parameters of the Savitri watershed considering two datasets, i.e., topographical sheet and digital elevation model over two time periods. The Savitri is designated as a seventh-order basin with a dendritic pattern covering a total area of 1966.34 km2. The average bifurcation ratio is 3.8 which confirms that the network of the drainage in the basin is not regulated by the underlying rock structure. Moreover, the drainage density and stream frequency values have shown marked changes that might be attributed to both natural and injudicious human activities, thus affecting the nature of the basin. The relief analysis of the basin indicates that most of the areas of the basin have gentle to flat gradient favoring frequent flood events.
This paper aims to explore the influence of feng shui factors on the house buying intention of Malaysian Chinese. According to the instrumental view of feng shui, prospective purchasers believe that feng shui arrangements can affect luck and fortune. A survey questionnaire based on the 24 criteria in the feng shui design framework was used for data collection from two different locations, namely Kuala Lumpur and Sandakan. The respondents cited feng shui as the third important factor in buying a house. Chi-square tests of independence show that there is a significant relationship between location of respondents and housing price, whereas location of respondents has no significant relationships with the other criteria for buying a house such as feng shui consideration. Independent-samples t tests were conducted to investigate if the respondents’ perceptions on the favourability of feng shui factors from the two locations were significantly different. The respondents indicated that houses with sea view, solid wood front door, of regular shape and well-lit living room as favourable. Whereas a house facing a cemetery, built on land with an irregular shape, with a smaller main door and bedroom located at the end of corridor have been found to be the most unfavourable for surrounding environment, external layout, internal layout and interior arrangement respectively. Both chi-square test of independence and independent samples t tests show that the perceptions of feng shui between the respondents from Kuala Lumpur and Sandakan are not significantly different from each other despite geographical differences. The findings can be used by property developers in their future property developments and by architects when designing houses.
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Slope stability is one of the focal areas of curiosity to geotechnical designers and also appears logical for the application of probabilistic approaches since the analysis lead to a “probability of failure”. Assessment of the existing slopes in relation with risks seems to be more meaningful when concerning with landslides. Probabilistic slope stability analysis (PSSA) is the best option in covering the landslides events. The intent here is to bid a probabilistic framework for quantified risk analysis with human uncertainties. In this regard, Fault Tree Analysis is utilized and for prediction of risk levels, consequences of the failures of the reference landslides have been taken. It is concluded that logics of fault trees is best fit, to clinch additional categories of uncertainty; like human, organizational, and knowledge related. In actual, the approach has been used in bringing together engineering and management performances and personnel, to produce reliability in slope engineering practices.
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Slope engineering is nowadays in great demand of proper risk management. Predictions regarding slope performances are subjugated by uncertainties. This includes uncertainties related to soil properties, model uncertainties and human uncertainties. In this study author discusses reliability analysis principles in relation with conventional practices and to prove its efficiency three case studies of Malaysian slope failures has been taken for further clarification. It is also mentioned that the concluded probability of failure still needs more refinement as no human uncertainties has been considered in this probabilistic analysis. Probabilistic analysis afford greater insight into design reliability, hence, supporting the engineering judgment and recuperating the decision making process. So, the intelligibility, effortlessness and cost/time effectiveness are indispensable essentials in order to successfully express and commune a probabilistic methodology to practicing engineers .
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Malaysia is characterized by a humid tropical climate with heavy rainfall. The annual temperature varies from 26 to 28°C while Malaysia is being one of the wet climate countries with as annual rainfall is approximately 2250 mm/year. Malaysia monsoon is arranged into two rainfall terms: the primary one coincident with the northeast monthly precipitation (December-March) and the other one with the southwest monthly rainfall in conjunction with inter-monsoon periods (April-November). The rainfall events are gauged at points of precipitation measurement networks in Malaysia. But, there is not full mapping of precipitation in relation with elevation all locations especially in mountains. This paper provides the relationship between monthly precipitation and elevation in the Hulu Kelang area based on Geographically Weighted Regression (GWR) method. Three periods of precipitation" the average monthly rainfall and two monsoons" has been studied in this area. The results of regression analyses performed between three conditions of monthly precipitation in the year and altitude. The mean absolute error (MAE) and the root-mean-square error (RMSE) verification results indicated that the whole year rainfall regression model works quite better than other results for interpreting the spatial variability of precipitation. The relation between original normal precipitation (1990-2010) and topography variables showed that study area precipitation is strongly controlled by elevation in the west region. The final map was represented that precipitation in the west region is generally higher than in east region of Hulu Kelang all around the year.
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Input parameters and models (in the form of limit state equations) in coastal engineering are influenced by uncertainties. The imperfect knowledge of these parameters may result in an underdesign and a failure of a coastal structure but may also result in an expensive overdesign. Therefore, the uncertainties of the stochastic parameters and models should be considered for probabilistic coastal structure design. The present paper summarises results of an expert judgement having the objective to quantify uncertainties related to coastal structures design based on a wide range of expertises.
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A number of fatal landslides disasters have been reported in Ulu Klang starting with the tragedy of Highland Tower collapse in 1993, followed by several landslides adjacent to the Highland towers. These landslides have resulted in casualties and loss of lives, notwithstanding displacement of residents and extensive damage to properties. In view of formulating a medium term and long term measures towards an effective policy of inspection and monitoring of development in the Ulu Klang areas, Malaysia Public Works Department (JKR) Slope Engineering Branch have commissioned an area based landslide hazard assessment study at this landslide prone location. The proposed study covers an area of about 100km 2 from Cheras to the North of Taman Melawati and the duration of the study is twelve months. Geographical Information System (GIS) is proposed to be used as the based machine for the production of landslide hazard map. LiDAR (Light detection and Ranging) survey was selected to produce the base map for the landslide hazard assessment. This paper highlights the landslide hazard assessment methodology and hazard map preparation using GIS application.
When there is an estimate of the probability of static failure for a set of slopes, based on historical records, maps, and subjective judgment, it is often necessary to estimate the additional hazard presented by earthquakes. Combining the procedures of reliability analysis with conventional recurrence relations for horizontal earthquake accelerations leads to a simple formulation that is easily implemented on a spreadsheet. For simple failure modes the dynamic factor of safety is a simple function of the static factor of safety, the amplified acceleration the slope of the failure surface, and the friction angle. Application of the technique to the slopes of the Montes de Caneja in Puerto Rico indicates that the additional risk due to earthquakes is about one tenth of the static probability of failure, but other sets of input parameters can give probabilities of failure during earthquakes that are comparable to the static values.
This paper presents an overview of the evolution in structural and geotechnical design practice over the past half a decade or so in relation to how uncertainties are dealt with. For the general reader who is encountering reliability-based design (RBD) for the first time, this would provide a valuable historical perspective of our present status and important outstanding issues that remain to be resolved. The key elements of RBD are briefly discussed and the availability of statistics to provide empirical support for the development of simplified RBD equations is highlighted. Several important implementation issues are presented with reference to an EPRI study for reliability-based design of transmission line structure foundations. Reliability-based design, simplified or otherwise, provides a more consistent means of managing uncertainties, but it is by no means a perfect solution. Engineering judgment still is indispensable in many aspects of geotechnical engineering – reliability analysis merely removes the need for guesswork on how uncertainties affect performance and is comparable to the use of elasto-plastic theory to remove the guesswork on how loads induce stresses and deformations.
Slopes within infrastructures sometimes slide and cause damage and inconvenience to the public. Some of these landslides have claimed lives. Landslides include newly completed slopes, such as the recent failure at Putrajaya as well as old slopes, such as the collapse of the rock slope of the PLUS Expressway at Bukit Lanjan (2003), which was completed more than ten years ago. The most notorious one was the collapse of a slope with rubble walls bringing down the Tower 1 Apartment of Highland Towers and killing 48 people on 11 Dec 1993. The towers were built in 1978. A review of the causes of landslides indicates that most of the landslides are man-made slopes and are mainly due to design deficiency (Gue & Tan 2006). This keynote also discusses some of the recent and older failures, the causes of failures, and outlines some suggestions to mitigate future occurrence.