- Md Arman Chowdhury added an answer:3Is there adequate literature on load transfer mechanism of inclined reinforced concrete column between two floor plan?
I am not getting any literature on this topic. As I want to do research on load transfer mechanism so I need some literature on inclined column research?
Also I want to know the scope of future research on this topic
Please help me in this regard
Dear Tiong, Thanks for your thoughtful explanation. But, I want to research on this topic as sometimes use of inclined column becomes obvious and what should be the load transfer mechanism in that case. Thanks again.Following
- Mohamed Aboelseoud added an answer:2How can I obtain a considerable deflection in in our bridge model?
We are designing an open web steel girder bridge of span 15m. The dimensions of the bridge are 15m x 2.6m x 3.8m. The bridge is a scaled down version of a Standard 30.5 m Indian Railways Bridge. The final objective of constructing this model bridge is to analyse the behaviour of the bridge and monitor its deflection, acceleration under loading. We would be using wireless strain gauge sensors and accelerometer sensors to record the deflection and acceleration respectively. However, the deflection which we are obtaining using point load of 5KN at 10 nodal points is 0.35 mm. This deflection is too less to be sensed by our sensor. Please suggest any way to obtain atleast 5 mm of deflection
The loads in your model seem to be small. I'm not familiar with the Indian code. But according to AASHTO LRFD 2012 the live load on a bridge consists of (a three axle design truck loads or design tandem loads) combined with (design lane distributed load). The design truck axle's loads are 8, 32, and 32 Kips. The total load of these axles are 72 kips. These loads are multiplied by dynamic allowance factor, which is about 1.33 leading to design truck load of 96 kips (427 KN) before adding the lane load. The total loads in your model is only 50KN which is significantly small. I suggest that you check your design load again.
- Olivier Vassart added an answer:6What are the main causes for construction budget overruns in the UAE construction market in the last 3-4 years?
What are the main causes for construction budget overruns in the UAE construction market in the last 3-4 years?
The largest problem is that many companies are really stretching the budget when they offer for the tender in order to be sure to be chosen and then, during construction, they increase the costs. Moreover, construction time with concrete based building are really too long and bring uncertainties on material, energy and manpower prices on the length of the construction (sometimes several years for tall buildings).Following
- Russel Donohue added an answer:13Can we ensure as per standard design the life span of Civil Engineering Structures, Residential Building, Commercial Building, Industrial Building ?
Nowadays Different Recycling material and chemical are Used for Construction with Respect to Confidence of Lab Testing Result .
But I am wondering , Olden days Without adding any Different Chemicals and recycling materials in the Construction activities, that Building life was as per standard design Life Span Achieved ;
But Nowadays for Example In Concrete lot of chemicals , Recycling Materials are Adding for Construction activity , these type How can Achieved as per Standard life span of Building .
Each and every Chemicals are having Different Reaction Characters............................... .
This question begs for a simple answer, but like so many conundrums, has many unseen moving parts that cause the response to be complex and unique for each individual case. In your question, it is suggested that the lifespan of a civil engineering project or commercial building can be predicted like a 'sell by' date stamped on a perishable, manufactured foodstuff. This requires large, generalized assumptions that result in a large, generalized answer that satisfies those people interested in the general answer, not how long will a particular project will 'last'.
While a 'standard design life' is certainly required when dealing with the large herd of similar projects, to think that there is a 'standard design life' for a project picked at random is not realistic from my perspective as a practical architect. Individual project lifecycle length is affected by multiple factors during the conception, execution, and use of the project each of which act as a multiplier (positive or negative) to the length of the project lifecycle.
I will look at selected decision points for each of these 3 project stages from both an 'Olden days' and 'Nowadays' perspective, thus illuminating my point:
Conception: Olden days - use of materials and quantities of materials dictated by experience / rules of thumb for systems with a long track recorded (load bearing masonry walls for example, where the masonry is thick enough that moisture can not travel through the system over a season so there are little surface condensation issues) versus 'nowadays' - new materials with projected, engineered characteristics that do not have an extensive track record, thus long term consequences are not fully understood.
Execution: Olden days - things were built like the buildings that stood the test of time the longest. Nowadays - new materials require new ways of construction with unintended consequences. The failure of residential construction with the use of EIFS (exterior insulation finish system) which forces wood stud buildings to rot from the inside out due trapped water.
Project Use: Olden days - time tested materials are handled and maintained as tradition requires. Rethatching roofs on a regular basis for instance. Nowadays - New products require new ways of dealing with them, which doesn't happen with users that are ignorant of new, required ways of dealing with new materials.
In addition to these introductory points, as building cost increase, the building industries use less and less durable materials, less of them, and put them together faster, generally with little skill. Meanwhile, olden time construction techniques use more materials typically, providing a better cushion for the building to use up over time, extending the building life.
These points add to less assurity in the resilience of the completed building, thus less assurity in the projection of a given building's useful life.Following
- Douglas D. Gransberg added an answer:7How do we use FWD data as a tool for controlling the structural capacity of pavements in Design-Build contracts? What can be a good controlling index?
An issue that has come up recently in our technical meetings is the use of FWD measurements as a tool for controlling the structural capacity of the pavements in our Design-Build projects. Since a few years ago we have started with this kind of contracts for both new and rehabilitations (bearing capacity improvement) projects in which we only set functional requirements (rut formation, cracking, IRI) during the guarantee period and no specific structural requirement is set on the . The guarantee period in our current Design-Build contracts are 10 years due to socioeconomic aspects.
The 10-year guarantee period is not very favorable for us from the technical point of view as there is a risk that we get pavement structures that are not very robust and require relatively high maintenance costs after the guarantee period is over. Therefore, we are looking for developing a method in which we can indirectly set structural requirements for the design through use of FWD data for our road network. Currently, we conduct FWD measurements shortly after opening of the road to traffic, but this is only done for the sake of documentation and no requirement is applied using the FWD measurements for the approval of the product.
1. I am wondering if similar kind of contracts are used elsewhere? If yes, do you apply any structural requirements to approve the final product in such contracts?
2. Is FWD used for such purpose?
3. Any suggestion on how we can develop a suitable method through use of FWD data for setting structural requirements in Design-Build Projects?
Interesting question. I believe there is no "magic bullet" to solve this issue and it is not confined to DB projects only. Pavement performance over the long term is more a function of the base on which it is laid, the traffic, and the environment. We engineers have convinced ourselves that we can make meaningful mechanical measurements like FWD to check quality but unfortunately the scale of highway construction and the inherent variability in the materials defeat these measurements, regardless of the statistical sampling rate. The only place where I know that a different system for pavement performance has been implemented to a reasonable degree of success is New Zealand. In NZ, the contractor's payment is linked directly to long-term actual pavement performance, but to do so, the client has to also allow the contractor to maintain the road it builds.
- Rawand mohammed Badri added an answer:9Could anyone here help me find some research papers and books regarding "Road construction"?
I want to study road construction techniques in detail, if any of you have any research papers or a good book about it please tell me, I would appreciate your help and support.
- Ugochukwu Okonkwo added an answer:7How do you justify the reduction of compressive strength of concrete when water-glass is used as the binder?
I worked on water-glass as the main binder instead of cement.It is investigated that compressive strength is decreased in comparison with cement type II as binder. I am seeking for some references such as papers and books which prove this fact. I appreciate you due to your answers beforehand.
- Dear Sasan, I understand that the major compound responsible for strength in cement-bound materials is calcium silicate hydrates. This might be lacking in the matrix formed with water glass because you used it as a binder unlike cement that possess much of calcium compounds that will produce these compounds responsible for strength.
- Ferdous Ahmed added an answer:3What would be a good resolution of DEM for large area wastewater modelling?
Area of Modelling: around 1000sq Km. Network length around 200 KM.Modelling for planning purpose of wastewater management. what resolution of DEM would be suitable for the same?
my experience is that a 10 m x 10 m DEM is good enough for delineating catchments for hydrological modeling. For hydraulic modeling (such as cutting river cross-sections), you would need higher resolution DEM.Following
- Sirous Yasseri added an answer:7Can someone provide me with some info. about the bias factors (mean/nominal value) adopted in US or Chinese (or any other country's) design code?
Can someone kindly tell me the value of the bias factor used in any American (or any other country's) design codes and most importantly where I can find these values?
And can someone kindly provide some info. about how the design codes determine the mean value and the standard deviation of the strength of materials, the loads and even the error in dimensions?
It seems you are looking for data and see how the statistical distribution of of various parameters, governing the design, are determined. Links in my first communication give you some information, not all of it. the following link a paper Fred Moses explain the concept of using reliability to calibrate API code. If you can find his earlier papers cited in that paper, you will find more detail, but all of them are older than you.
You will find some answer to your question in this document.
Partial safety factors (both load and resistance) have been derived based on a mixture of fresh data and their statistical distribution, and previous codes in existence. Partial safety factor were originally set for the modern code so that results to be similar to the old code. Such parity has gradually been eroded in the later version of codes.
- Mu'ath Tarawneh added an answer:4How I could find the load distribution effect on sensor in transverse direction for vehicle running on longitudinal direction?
I have a two-dimension sensor use to find the strain in concrete plate while the truck runs in x-direction, it run over the entire length of longitudinal sensor. In this case what the effect of this load on transverse sensor.
it is 3D sensor designed to yield vertical loads in 3 direction.Following
- Adriana Camargo de Brito added an answer:11Why do construction projects fail to achieve energy targets?
Buildings often initiated with the plans of reducing energy during its construction and operation period fail to achieve the energy targets.
- Christopher Beckett added an answer:10What is the best curve fitting method for SWCC by (Fredlund and Xing,1994) and (van Genuchten,1980-Mualem,1976)?
I have SWCC by (Fredlund and Xing,1994) and now I would like to estimate the a and n parameters in (van Genuchten,1980-Mualem,1976) using curve fitting. The critical part is a as it will be taken as 1/a in (van Genuchten,1980-Mualem,1976). Can anyone shed some light on this please? Thank you.
Presumably you are testing a sand and have data in the residual range? If not then you're going to have a hard time! There are lots of examples of FX use in the literature and some good FX fit examples in "Unsaturated properties of recycled concrete aggregate and reclaimed asphalt pavement" by Rahardjo et al. - he is an excellent researcher, so that might be a good place to start.
- Prajyot Bodhale added an answer:2How can we model an RCC Beam in ANSYS?
I want to model an RCC beam in ANSYS and also want to give the incremental loading on beam so that I can plot a graph of crack width Vs load and crack depth vs load. Thank you.
thank you sir i had modelled the beam with solid 65,solid 45 and link 8 element.The Solid 65 for concrete,solid45 for support plate, and link 8 for reinforcement it workedFollowing
- 1What is the best way to measure the slip of longitudinal steel bar in beam-column joint?The test is interior beam-column joint under reversed cyclic loading. What is the best method to measure the slip of longitudinal steel bar in joint?
Thanks very much!
The best but laborious method is to integrate the strains in steel and concrete along the test length of the bar.Following
- 1How to model external prestressing in abaqus?I want to model external prestressing in cantilever bridge.
I use rebar layer for internal prestress but I don't have any idea about external prestressing.
You can treat it as initial stress problemFollowing
- Jignesh Rajnikant Mehta added an answer:5How do I calculate heat loss by evaporation from the surface of an active swimming pool?
How do I calculate heat loss (in kW) by evaporation from the surface of an active swimming pool for a hotel? Taking factors like wind speed, pool surface area and pool utilization factor into consideration .
You can use the standard correlations for flat plate, find Sherwood number to get mass transfer coefficient.
Use this, area and water vapour pressure (or water vapour density) difference to get the rate of mass loss. Ref: Heat and Mass Transfer by Incropera and De Witt.Following
- Tom Haywood added an answer:3Does anyone have any resources or suggestions for the analysis of stresses induced by shafts upon masonry tunnel linings?
I am looking to carry out an FEA of the above (see Clifton Hall Tunnel colapse) as part of my master's dissertation. This is an area of little to no research and forming the basis of a literature review is proving difficult, any help would be welcome.
The remit of my analysis is strictly theory based at this stage as I do not have the available time and resources for lab analyses. Any previous work of a similar nature would be helpful for my literature review, my employer (a design consultancy) has recently specified a remedial works for grouting around the tunnel annulus at a shaft location where the surrounding strata is not in contact with the lining and therefore not effectively restraining the arch element of the tunnel structure, the point of the FEA is to present a case for this remedial measure (a "sales tool" if you like).Following
- Jesús Rafael Hechavarría Hernández added an answer:1How can I determine variation of shock over pressure along length in tapered driven section?
While designing shock tube of variable cross sectional area of driven section I am interested in determining variation of shock over pressure along the length of driven section (variable cross section). So, how can I find ?
Thanks and Regards,
The energy loss is calculated using the Bernoulli equation. You must consider that for pipes of variable section, the velocities in the initial and final points of the conduit are different, so you must take into account the equation of the kinetic energy v2 / 2g.Following
- Behzad Rezaei asmarood added an answer:3Are there any guidelines which define the sizes/slenderness ratios of prefabricated wall panels used as non load bearing elements?
Are there any guidelines which define the sizes/slenderness ratios of prefabricated wall panels used as non load bearing elements?
The prefabricated walls are like sections under bending and pressure. then conditions found in the ACI 318 can be used to them.
I believe .Bearing and non-bearing members have the same conditions about slenderness and thickness.because non bearing load sections should carry self weight , Sometimes wind load.Following
- Daniel Tregnago Pagnussat added an answer:4Besides ASTM C270, are there any others standard that can be used to classified mortar?
Besides ASTM C270, are there any others standard that can be used to classifiy mortar?
Related Brazilian Standards
ABNT NBR 13281 - Mortars applied on walls and ceilings - Requirements
ABNT NBR 13749 - Render made of inorganic mortar walls and ceillings applications - SpecificationFollowing
- Martin Baeker added an answer:3How can I get the number of iteration from Umat written in A text file?
I am writing the Abaqus' output such as stress and strain in a text file. I need to use these as training data. However, the results are repeated and given different set of data because of the differences in the number of iteration.
In the text file I can have the number of elements, increment number and variables but I need the number of iteration as well?
Does Abaqus in Umat output give me just the last iteration?
The attached texts show the data is repeated twice for on iteration and triple for two iterations? (Number of element = 15)
Could you please advise me ?
Look at the msg-file or the sta-file to see how many attempts are made per increment.
Somewhere in the manual there is an explanation of when the UMAT is called, this should then tell you exactly what happens here.
In any case, for output, an UEXTERNALDB is probably the routine of choice.Following
- Viktor Vladimir Chistyakov added an answer:20Examples of Higher Order Systems of Differential Equations?
I am trying to find examples of systems of linear higehr order differential equations.
That is, systems in the form;
Α Χ'''(t) +B X''(t) + C X'(t) + DX(t) = U(t)
Α Χ'''(t) +B X''(t) + C X'(t) + DX(t) = 0
where A, B, C, D are matrices and X(t) is a vector variable, i.e.
Χ(t)=[v1(t) v2(t) v3(t) ]T
Many such systems arise in mechanical engineering, like spring-mass oscillation systems, spring-mass systems with dampers etc, but all of them are 2nd order differential equations.
Can anybody help me find systems of order 3 or higher? The free parameter t does not necessarily have to be time. They can be engineering, biological, economic systems, whatever!
Please provide references too.
Not only. There are more works where the III-rd order DE are considered but in Russian. Namely, the problem of point projectile trajectory in air with density and gravity linearly decreasing with height, the particular case of dynamically disbalanced rotator with combined friction ( both see Bulletin of Udmurt State University, Maths, Mechs&Comp.Sci.). The problems may be 'matriced' by substituting the point by symmetrical body.
Though the equations are nonlinear they may be linearized.
- Hernan Garcia added an answer:7How we can normalize our shape modes with dynamic stiffness matrices without having any mass matrices directly?
I am looking to normalize the shape modes of a Euler-Bernoulli beam in spectral element method. The difference between this method and FEM is we have only dynamic stiffness matrices instead of mass and stiffness matrices. As you know, in FEM we use the mass matrices to normalize shape modes. What should I do now?
Thanks for your attention
It depends on your porpoise, you can normalize them against roof displacement.Following
- Saurabh Deshpande added an answer:7What are the different methods (experimental and theoretical) to determine tensile strength of clay or sand in saturated and unsaturated condition ?
Different experimental and theoretical methods that are used in practice to determine tensile strength of sand and clay in saturated and unsaturated condition.
thank you Kundan sirFollowing
- Sujan Shrestha added an answer:6Can anyone kindly link me with guidelines of repair and restregthening of historic URM buildings?
Specially for traditional and historic buildings.
Thank you Meta for your suggestionFollowing
- Greg White added an answer:3How can I use the normal stresses developed on an interface to assign other properties to the interface elements?
I want to define variable properties on the interface using the Mohr-Coulomb criterion (so, I need to enter as input the cohesion, friction, normal and shear stiffness of the interface, but i have these properties depending on the normal stress on each interface). Also, i want to know if exist a variable to select the stresses at interface, in order to be able to create a FISH for this purpose.
I assume you refer to the interface between the surface and underlying asphalt layer in a road or other pavement.
As you say, the properties you require are a function of the normal or confining stress. You can estimate this based on finite element or layered elastic theory. I have regularly used the layered elastic tool mePADS (from South Africa) for such calculations, which is adequate for studies based on 'relative comparison' (eg. comparing braking to non-braking conditions). If you don't have access to such tools, you could estimate the normal stress using very simple Boussinesq equations.
It is important to remember that the normal and the shear stress varies under the tyre footprint. Stress-to-strength ratios can be calculated over a grid to determine the critical location. Near the surface, this is generally just in front of the cente of the tyre, where the shear stress is high and the normal stress is low.
It is also important to acknowledge that the interface properties (strength, modulus, cohesion, adhesion) vary widely based on tack coat materials, interface texture, curing conditions and temperture. It is essential to characterise your specific interfaces by direct shear testing, which generates cohesion and adhesion properties, as well as modulus and post-elastic friction.
There are many publications on this topic, and I am happy to provide the citations if you make direct contact.
- Khurram Shahzad added an answer:5What is this error in abaqus?
Detected lock file Job-1.lck. Please confirm that no other applications are attempting to write to the output database associated with this job before removing the lock file and resubmitting.
Thanks and regards,
A lock file indicates that Abaqus is processing the file in background even if you kill it. so renaming the Job does not work in most cases. But there is another possibility that some of your application file is still running in background. Use Task Manager and first kill the Abaqus file which named as (SMAXpl_SP). and than re-run your abaqus program.Following
- Ashish Guruji added an answer:15How do I measure workablity of fresh concrete?
I found shear vane test has been used more recently instead of slum, compacting factor and flow tests
slump test will give you workability of fresh concrete
the height of slump 30 cm and it is measure from top,
after filling concrete in cone , how much settle from top is measured.
for dense reinforcement high slump value prefered for mass concrete less.Following
- Umer Farooq added an answer:3What is the best way to find information/documentation on ancient bridges from 1000 AD and older?There has been historical mention of the construction of bridges in ancient societies even in B.C. times, but I have yet to find any documentation on any specific bridges from this time period. I am interested in learning more about these ancient bridges, but as most of these bridges are not still in existence I'll have to rely on documentation on the existence of these structures, or archaeological evidence proving they existed. How would I go about finding this information?
This documentation will be helpful to you.Following
- 1comparison of L column with square column and its structural behaviorIn india l column is not used but it usage is advantages in many uses .so, interested to know about it.
Square columns are usually used where the eccentricity of the acting load is very small or nearly zero (this case is very rare in practice). It is used also when the bending moments acting at two perpendicular directions are nearly equal (this case occur when the beams supported by the columns have nearly equal loads and spans). In the two previous cases the reinforcement are distributed along the four faces of the cross-section.
L shaped columns are usually used in corners of buildings when the spans of the exterior beams are relatively large and creating large bending moments. Care must be exercised in distributing the reinforcement.Following
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