ASSESSMENT NO. 2 INTERPRETATIVE REPORT (75%):
Each student, acting as a Geotechnical Consultant, shall prepare an individual interpretative report on a site investigation for the construction of a small reservoir and associated structures, as shown on drawing Site Plan Appendix I. The area of land under consideration comprises the confluence of two streams into a relatively high sided valley. It is proposed to dam the valley at its narrowest point by the construction of an earth dam, together with two spillways and a pumping station. An access road is also to be constructed to serve the pumping station.
A factual report has been prepared by Rogers Geotechnical Services Ltd and this document has been issued as part of the general information relating to the site. The aims of this report are to outline the structural properties of the site in relation to the proposed development, carry out initial design calculations for the proposed work, advise on any problems that may occur on the site during and (or) after construction and suggest justifiable ways of overcoming any problems identified. Both hand and/or computer calculations are required for certain sections below, together with written comments comparing the result obtained from both methods.
The presentation of the report must be to a very high and accurate standard i.e. you are employed by the client to produce a series of professional design calculations marks will be deducted if this is not achieved.
Each student must individually complete the following sections:
Strata Conditions (15 marks hand calculations together with AutoCAD drawings)
Produce a detailed geological survey plan and cross sections for the site, including angle of dip and strike for the main coal seam. Comment on the strata sequence and geotechnical/geological conditions beneath each element of the development, summarising the geotechnical properties to be employed in the design of each section of the work.
Earth Filled Dam (25 marks both hand and computer calculations are required, i.e. compare and contrast any disparities between your calculations)
8 m
The dam is to be located as shown on the site plan and its preliminary design is provided below:
CLAY
0.5 m
13 m
34 m
The clay fill consists of brown slightly sandy silty CLAY, which is to be compacted in layers using a sheepsfoot roller to provide a low permeability structure.
The calculations shall include the rate of flow through and beneath the dam, with comments on the results and including any remedial measures that will be required to ensure the stability of the dam structure, including a design check for piping. Also, estimate the total magnitude of settlement of the dam.
Slope stability (25 marks only computer calculations are required, however two different computer packages should be used. Oasys should be used to undertake an EC7 check on all elements (dam and reservoir), and Slope/W together with SEEP/W should be used to produce a couple analysis in respect to drawdown conditions for the dam only.
Assess the long-term stability of the reservoir valley sides (including rapid drawdown conditions). In addition, assess the long-term stability of the dam, both up and down stream, assuming the dam is empty, full of water and subject to rapid drawdown (instantaneously as well as over a period of 30 days).
Spillways (10 marks hand sketches and hand calculations are required)
Sketch a suitable spillway structure and then estimate its total weight before undertaking a suitable foundation design and settlement analysis.
Pump House (10 marks hand calculations for bearing; computer calculations for settlement)
The pump house is to be constructed on a 30 m x 20 m raft foundation, which will impose a stress of 35 kN/m2 to the underlying soil. Estimate the overdesign factor against bearing resistance together with the overall settlement of the structure.
Retaining Wall & 7. Proposed Road sections have now been removed
In any of the above calculations, if any unsafe design values are obtained develop a solution to ensure failure does not occur.
Deadlines and rules:
The submission dates area:
Laboratory report: 5/6/20 by 15.00 (uploaded to MyBeckett)
Interpretative report: 29/5/20 by 15.00 (uploaded to MyBeckett).
Please scan or take pictures (using your mobile phone) of any hand drawings and embed them into your report and upload to MyBeckett.
You must upload the text sections of your reports (both lab and interpretative) to Turnitin, via the icon on the geotechncial engineering module on My Beckett and obtain an originality report. That is, the document you upload to Turnitin must exclude: drawings, calculations, tables, page headers/footers, etc.
This Turnitin originality report must be included at the start of your Laboratory report and Interpretative report. Failure to include it will result in a default mark of zero being awarded. NB you can only upload one document in a 24-hour period, i.e. to prevent you from tweaking the report the night before it is due in. If a high percentage is returned in the similarity index marks will be deducted, and you may also be investigated regarding plagiarism/collusion. NB the software can detect similarities between your report and your colleagues, as well as published literature (whether paperbound or web-based); hence do not copy! Normal university rules regarding late submissions shall apply.