Coursework Description

 

 

 

 

1.      Assignment brief

 

Wind power is a vital component of low carbon energy generation. A substantial proportion of the capital expenditure required for the installation of new wind turbines is concerned with their foundations and the associated ground works.

 

A prospective site for a wind turbine is located at National Grid reference: 333220, 446288. An initial series of ground investigation works have been undertaken. You are to carry out the tasks of: (a) interpreting the data obtained from the initial ground investigation and (b) recommend the detailed schedule of sampling and laboratory testing that should be carried out to provide the data necessary to characterise the geotechnical conditions fully in readiness for the siting of the wind turbine.

 

The dataset on which your report is to be based is enclosed in the Appendix. The dataset consists of visual records and measurements obtained from an exploratory borehole that has been drilled on site. The dataset consists of the following:

 

1. The borehole core log visual This is provided in Section A1.
2. Raw data obtained from a set of sieving analysis carried out on samples extracted from the borehole core. This is provided in Section
3. Atterberg limit test results obtained on the samples extracted from the borehole core. This is provided in Section
4. Standard Penetrometer Test results obtained during the drilling of the borehole. This is provided in Section
5. Speculative undrained strength measurements taken at nearby locations. This is provided in Section
6. Contamination data obtained from a sample extracted from a nearby trial This is provided in Section A6.

 

Your report should be of a maximum length of 2500 words and should include the following:

 

1. A brief introduction providing some context on the need for detailed ground investigations before finalising the choice of site for a new wind

[suggested maximum number of words: 150]

 

2. A description of the basic geography, current land use and regional geology (as interpreted from geological maps) of the site, drawing out any relevant aspects of the geographyƒland useƒregional geology that are likely to affect the viability of the location as a site for a wind

[suggested maximum number of words: 300]

 

3. Classification of the local geology at particular depths, based upon the results of: (i) sieving tests and (ii) Atterberg limit tests obtained from samples extracted during the drilling of an exploratory borehole. This section of your report should include particle size distribution (PSD) plots and your classification should be made with recourse to the British

[suggested maximum number of words: 200]

 

4. Plots showing: (i) the variation of Standard Penetration Test N−count against depth below the ground surface and (ii) the variation of friction angle against depth (as deduced from appealing to a correlation between N−count and friction angle). Some comments on the suitability of such correlations should be

[suggested maximum number of words: 50]

 

5. Discussion on how the SPT data fits with the regional and the local geology [hint: where is the likely interface between the superficial deposits and the bedrock?]

[suggested maximum number of words: 200]

 

6. Brief comments on the significant of the contamination data

[suggested maximum number of words: 200]

 

7. Discussion on the characteristics of the ground that are likely to be important in the context of the ground being used to support a wind You should also provide some discussion on which geotechnical parameters it would be useful to determine values.

[suggested maximum number of words: 500]

 

8. Comment on the likely impact of the speculative undrained shear strength parameters [Hint: 13kPa represents a soft soil, and would be unlikely to be sufficient to carry the loading imposed on it by a wind turbine]

[suggested maximum number of words: 200]

 

9. An account detailing the schedule of sampling and laboratory testing that should be carried out to fully characterise the ground Your account should include:
   1. The types of tests that should be carried out in the laboratory;
   2. The testing conditions that should be imposed and an explanation of their importance (e.g. rates of loads, magnitudes of confining pressure);
   3. An explanation of how the tests would provide the parameters needed;
   4. Relevant details pertaining to the sampling

[suggested maximum number of words: 700]

 

• Just to provide clarity with regard to the coursework assignment; the location in question has a 6 figure National Grid reference of: SD332462 (Easting: 333220, Northing: 446288; Latitude: 53.908425, Longitude: -3.0180137).

 

 

2.      Some suggested resources:

The main resources needed for your assignment are textbooks or Geotechnics. Some recommended textbooks include:

Basic Soil Mechanics by R. Whitlow; Fourth Edition, 2001; PearsonƒPrentice Hall Craig’s Soil Mechanics by J. Knappett & R. F. Craig, 2013; CRC Press

Soil Mechanics: Concepts and Applications, 2^nd Edition; William Powrie; Spon Press You will also be required to access geological maps using the BGS website:

 http:ƒƒmapapps.bgs.ac.ukƒgeologyofbritainƒhome.html

 

 

 

3.      Assessment criteria

The table below provides a breakdown of the worth attributed to each section.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

	A brief introduction providing some context on the need for detailed ground investigations before finalising the choice of site for a new wind turbine	A description of the basic geography, current land use and regional geology (as interpreted from geological maps) of the site, drawing out any relevant aspects of the geographyƒland useƒregional geology that are likely to affect the viability of the location as a site for a wind turbine.	Classification of the local geology at particular depths, based upon the results of: (i) sieving tests and (ii) Atterberg limit tests obtained from samples extracted during the drilling of an exploratory borehole.	Plots showing: (i) the variation of Standard Penetration Test N−count against depth below the ground surface and (ii) the variation of friction angle against  depth	Discussion on how the SPT data fits with the regional and the local geology	Brief comments on the significant of the contamination data	Discussion on the characteristics of the ground that are likely to be important in the context of the ground being used to support a wind turbine. You should also provide some discussion on which geotechnical parameters it would be useful to determine values.	Comment on the likely impact of the speculative undrained shear strength parameters	An account detailing the schedule of sampling and laboratory testing that should be carried out to fully characterise the ground conditions.
%	5	10	20	5	10	5	15	5	25
80− 100	Outstanding	Outstanding	Outstanding	Outstanding	Outstanding	Outstanding	Outstanding	Outstanding	Outstanding
70− 79	Excellent	Excellent	Excellent	Excellent	Excellent	Excellent	Excellent	Excellent	Excellent
60− 69	Very good	Very good	Very good	Very good	Very good	Very good	Very good	Very good	Very good
50− 59	Good	Good	Good	Good	Good	Good	Good	Good	Good
40− 49	Adequate	Adequate	Adequate	Adequate	Adequate	Adequate	Adequate	Adequate	Adequate
35− 39	Poor	Poor	Poor	Poor	Poor	Poor	Poor	Poor	Poor
30− 34	Very poor	Very poor	Very poor	Very poor	Very poor	Very poor	Very poor	Very poor	Very poor