Assignment Task
Task
Soil Structure Interaction
A-Plus Writing Help For University Students
Get expert assistance in any academic field. All courses and programs covered.
Get Help Now!Intended Learning Outcomes:
1. Select the most appropriate SSI model for a given application
2. Determine the data required for a given SSI model
3. Set up and analyse SSI models of continuous footings, rafts, laterally-loaded piles, and embedded retaining walls
4. Compare and contrast discrete spring and continuum models of SSI
5. Validate the solutions obtained from commercially available software packages
Overview
A reinforced concrete strip footing 10 m long, 1.5 m wide and 350 mm deep will be constructed on the surface of a thick deposit of clay. The footing will support a vertical knife edge load (KEL) of 750 kN per m width acting at a distance of 3.5 m from the left-hand end, and an anticlockwise moment of 250 KNm per m width applied at a distance of 3 m from the right-hand end, Figure 1.
A single percussion borehole was made on the site, from which U100 tube samples were retrieved and taken to a laboratory. There they were extruded and subjected to consolidated undrained (CU) triaxial tests, in which the in-situ mean effective stress levels were re-established for each depth before shearing, and from which the following soil parameters were determined. Based on the inferred overconsolidation history and plasticity index of the clay, Eu/cu for the clay was considered to be approximately 750. The groundwater level was just below ground level.
Specific Tasks
(1) Estimate the vertical deflections of the footing and the bending moments and shear forces acting in it, using both discrete Winkler spring (finite difference) and continuum (finite element analysis. It is suggested that you use one of the BOEF1 workbooks for the former, and PLAXIS2 for the later, but you are welcome to use software of similar functionality that you may be familiar with. In both cases, the footing will need to be modelled explicitly, but there is no requirement for any specific interface behaviour in the continuum analysis – which should be linear elastic to be directly comparable to the discrete spring analysis. Discuss your results, comparing and contrasting the results of the discrete spring and continuum analyses. You should also carry out an independent check on your results using an appropriate method.
(2) A more thorough site investigation has revealed that part of the site is occupied by a backfilled excavation around 6 m deep. Poorly controlled backfilling has produced ground that has a stiffness that is only about 50% of the surrounding clay. The left-hand 4 m of the footing rests on this backfill, with the remainder of the footing on the original clay, Figure 2.
Adapt both the continuum and discrete spring models set up in (1) to accommodate this backfilled zone and re-run the analyses with the same applied loading. [NB: a minor adjustment to the BOEF workbook will be required.]
(3) One of the limitations of the discrete spring model is that it allows tension to develop in the springs, such that if the beam was to lift off the ground the springs would try to restrain it. Modify the BOEF workbook used for the analysis in (1) so that tension cannot develop in any of the springs. Explain carefully what you have done to achieve this and any precautions that have to be taken whilst running it. When you are satisfied that you have made the required changes, rerun the discrete spring analysis from (1) and compare the results. Discuss whether or not you consider this modification to have been a worthwhile improvement. [NB: you are not required to re-run the continuum analysis.] You should submit the modified workbook along with your report as a separate file so that the correctness of the implementation can be verified.
Note: The information given above is not sufficient to perform the analyses. You will need to make judgements about appropriate geometric discretization, and any material properties not specified above (in particular, the coefficient of subgrade reaction). You should do this on the basis of the other study units in this module, your reading of relevant literature, and your engineering experience – providing clear reasons and justification for doing so. You should expect to have to do some background research for a coursework assignment at FHEQ Level 7.
This ENGM048-Engineering Assignment has been solved by our Engineering Expert at TV Assignment Help. Our Assignment Writing Experts are efficient to provide a fresh solution to this question. We are serving more than 10000+ Students in Australia, UK & US by helping them to score HD in their academics. Our Experts are well trained to follow all marking rubrics & referencing Style. Be it a used or new solution, the quality of the work submitted by our assignment experts remains unhampered.
You may continue to expect the same or even better quality with the used and new assignment solution files respectively. There’s one thing to be noticed that you could choose one between the two and acquire an HD either way. You could choose a new assignment solution file to get yourself an exclusive, plagiarism (with free Turn tin file), expert quality assignment or order an old solution file that was considered worthy of the highest distinction.
Welcome to our Online Essay Writing Agency. Securing higher grades costing your pocket? Order your assignment online at the lowest price now! Our online essay writers are able to provide high-quality assignment help within your deadline. With our homework writing company, you can order essays, term papers, research papers, capstone projects, movie review, presentation, annotated bibliography, reaction paper, research proposal, discussion, or another assignment without having to worry about its originality – we offer 100% original content written completely from scratch
We write papers within your selected deadline. Just share the instructions