Alsidqi Hasan

University Malaysia Sarawak · Department of Civil Engineering

Tropical sapric peat originates from highly decomposed woods. It consists of organic particles with colloidal microstructure and jelly-like texture. The complex fabric influences the permeability and the rate of pore water dissipation. The objective of this paper is to measure the permeability of tropical sapric peat using the flexible wall permeam...

Stone columns consist of granular material compacted in long cylindrical holes. They are used for improving the strength and consolidation characteristics of compressible soils. However, they are still less effective at supporting heavy loads, since they still cannot transfer applied stresses to deeper layers of soil. The main objective of this num...

Tropical alluvial soil has distinctive physical characteristics when compared to common sedimentary soils. Ignoring such distinctive characteristics might lead to geotechnical problems that require a thorough re-investigation. Foundation failures have been identified along some river banks of tropical alluvial soil deposits in Sarawak, Malaysia, wh...

Tropical alluvial soils have unusual engineering properties and their behavior is not typical of fine-grained soils. The literature regarding strength properties of alluvial soils is limited. This study presents an experimental evaluation of inherent anisotropy of undisturbed tropical alluvial soil samples by comparing the direct simple shear (DSS)...

Tropical sapric peat has a distinctive origin, which originates from highly decomposed woods. It consists of organic particles with colloidal microstructure and jelly-like texture. Such feature influences the permeability and the rate of pore water dissipation. This paper discusses the tropical sapric peat permeability behaviour from a series of fl...

Piled raft foundations are a common type of foundation for high-rise buildings. Unlike shallow foundations, deep foundations (piles) pass through weak or soft soil deposits and can reach stiff soil or bedrock to support the weight of the structure. In this paper, the performance of a medium embedment depth piled raft foundation in soft soil is pres...

The estimation of peat strength and compressibility properties is complex due to continuous changes in microstructure caused by decomposition. Decomposition significantly alters the fibre content and structural fabric arrangement in peat and is a significant factor in establishing the strength and compressibility characteristics. The present study...

In-stope paste backfill monitoring at different mine sites showed anomalous increase in total stress during rest periods. One of the explanations according to a recent laboratory- model experiment was attributed to volumetric expansion caused by temperature increase within the backfill. This paper extends the understanding whether the Mohr–Coulomb’...

In the last few decades, it has been observed that raft foundations are very commonly used as a foundation solution for moderate to high rise structures either by resting on stone columns or on piles in soft soils. It is believed that, combining stone columns and piles in one foundation system is the more suitable foundation for medium rise structu...

Stone columns are the most common and effective technique used for enhancing the overall strength and performance of soft soils. They are more effective for moderately lightweight structures. This investigation presents a parametric study of stone columns embedded in ground to strengthen the soft clayey soil under stiff raft foundation. This resear...

Peat is highly compressible, and it creeps significantly after primary consolidation. Hence, the knowledge of peat settlement characteristics is crucial for sustainable construction on peat. This paper presents the compressibility behaviour of the reconstituted tropical sapric peat specimens obtained via Constant Rate of Strain (CRS) tests by contr...

In general high-rise buildings are predominantly supported by piled raft foundations. Deep foundations (piles) are very effective for heavy structures because piles penetrate through the weak or soft soil deposits to the stiff soil or bed rock to support the structure weight. This paper aims to present the performance of piled raft foundation with...

Placing mine tailings back into underground mined-out stopes is becoming increasingly used internationally because it improves ore recovery, reduces dilution of valuable ore, and increases environmental benefits due to the reduced size of the storage facilities of surface tailings. In recent years, a number of stopes backfilled with cemented paste...

Uncertainties and difficulties surrounding laboratory strength testing of peat have caused the increasing reliance on in-situ testing methods, which include T-bar and ball penetrometers, to determine the undrained strength of peat for design purposes. This paper presents the results of miniature full-flow penetrometer (T-bar and ball) tests on deco...

The ASTM standard provides guidelines for the drained direct shear test (DST) and requires the samples to be sheared at rates estimated from time to failure, \(t_{f} \ge 50t_{50}\) (where \(t_{50}\) is the time required to achieve 50% consolidation). This paper investigates the potential of estimating the undrained strength of peat in the DST owing...

Rapid increases in the production of gypsum waste from the Flue Gas Desulphurization process necessitates that proper impoundments be built with an adequate understanding of the strength behavior of the sedimented gypsum slurry. This article presents laboratory experimental results that describe its physical characteristics and strength behavior. T...

Peat is viewed to deflect from the standard guidelines of soil behaviours due to the influence of structural fibres and high compressibility. Hence, the laboratory strength behaviour of peat is often complex, and the geotechnical test results may be doubtful. Amorphous peat is expected to behave differently since the fibres have been broken down in...

This paper presents a review of the advances in the variable penetration rate testing methods on inorganic soils and its potentials to investigate the appropriate penetration rate and resistance factors for penetrometer testing of peat. A partially drained condition, which often leads to misinterpretation of test results, has been observed in peat...

This paper presents preliminary results from a laboratory backfill model test in order to explain the effect of temperature change during the cement hydration on the total stress within cemented paste backfill. It is conducted via temperature control test in the absence of the cement. This investigation is an attempt to resolve an anomalous behavio...

A growing interest of sugarcane bagasse fibre composite has been observed in recent years due to its attractiveness properties such as low specific weight, renewable source and producible with low investment at low cost. However, these materials have a low interfacial adhesion between fibre and matrix which lead to reduction in certain mechanical p...

Cement as an essential element for cement-based products contributed to negative environmental issues due to its high energy consumption and carbon dioxide emission during its production. These issues create the need to find alternative materials as partial cement replacement where studies on the potential of utilizing silica based materials as par...

Aydin et al. introduced the weir velocity concept in 2011 for discharge measurement in contracted rectangular sharp-crested weirs. Gharahjeh et al. further reinforced this formula in 2015 to allow discharge to be computed using only weir velocity and crest width. These newly introduced expressions are tested and demonstrated to determine surface wa...

This paper investigates the distribution of intergranular forces within uncemented mine backfills using the discrete element method (DEM) and compares it with the existing analytical method. The virtual backfilling is modeled via the DEM to simulate the underground mining stopes backfilling with uncemented granular materials. Normal and shear force...

A constant-volume direct simple shear apparatus was used to investigate the effects of confining stress, initial static shear stress and void ratio on the liquefaction resistance of fine-grained tailings. The cyclic resistance ratio (also expressed as the overburden stress correction factor) was found to decrease with increasing confining stresses...

Cemented paste backfill CPB has been widely used in underground mining operations in the recent past for filling the voids (stopes) left after blasting and mucking of ore. It provides a series of advantageous environmental, safety and economic characteristics. However, several barricades failures have been reported in the recent past. This paper pr...

This paper presents in-stope measurements of total stress and pore-water pressure at strategic locations within three underground stopes at the Raleigh mine site (Western Australia) that were filled with cemented paste backfill (CPB). The three stopes were very similar in shape. Key differences among the stopes were the filling and resting schedule...