Table of Contents
PART A
The outcrop Z is exposed part of rock C. the exposure might have been caused by erosion which stripped off the overburden of layers A and B thereby exposing the underlying layer C forming such an outcrop.
The main structural feature in this area is the fault. The geological faults as noted in the map extends from the from the outer layer A into the third inner layer C through the intermediate layer B. faults in geological maps as indicate active zones in that area. Such active zones are lines along which catastrophic events such as earthquakes occur. Therefore geological structural features such as faults are of great concern as they indicate lines of weakness.
Water must have leached the clay material found in rock B from the layers above it. Looking at the extent of the faults in these rocks, the clay materials might have been washed down by the percolating water from the overlying layers into rock B.
PART B
Some of the relevant sources of information to be considered in desk study. During desk study, the following information sources would be considered; Maps generated from ordnance survey (Designingbuildings.co.uk., 2017). Such maps are topographical maps produced officially in the United Kingdom and provide detailed information about a specific area. The maps include historical maps of an area in question. A wide range of information can be obtained from these maps. For instance, these maps would point out changes that occurred in areas in which landslides are likely to occur. Any topographical changes and changes of watercourses such as rivers and streams that might have occurred would also be depicted in these maps. Information on coastal erosion and mine shafts that might have been concealed is also reviewed. Other types of data that would be obtained from ordnance survey maps include disused quarries, the drainage of the area as well as the former use of the area being studied.
Geological maps of the area being investigated (Designingbuildings.co.uk., 2017). Making use of these maps would provide information regarding the ground conditions of the selected site. Therefore such maps would give information of any risk of subsidence of the area and any possibility of the site failing by shear.
Recorded aerial photographs and Google maps (Designingbuildings.co.uk., 2017). Such photos and maps would give information of the former use of the area being studied as well as any topographical changes and variation of watercourses such as rivers and streams that might have occurred over time.
Use of services records as sources of information (Designingbuildings.co.uk., 2017). Such records would help in locating any hidden service including electricity and telephone cables as well as any laid drainage systems in the area.
The proposed site may not be suitable for the proposed development. The site is at risk of three potential hazards namely risk of subsidence and settlement, high water table and toxic debris. For instance, the proposed area for the community center is at risk of subsidence once structures are implemented in this area. The historic map shows that initially, this area was a quarry. There are high chances that the backfill material was not well compacted after the quarrying exercise was over. Therefore, the foundations of the buildings would be prone to settlement as the ground beneath the implemented structures would be settling upon the exerted pressure.
Presence of wells and springs near the proposed area for the community center and housing and parking as seen in the historic map is an indication that the site has high water tables. High water tables are hazardous conditions when proper measures are not taken. It weakens foundations of buildings and thereby subjecting the affected structures at risk of collapsing.
Moreover, there was a rifle range near the proposed area for housing and parking which was likely used during quarrying. There are high chances that quarrying was carried out over a long period given that the quarried area is relatively large. Therefore the prolonged use rifles must have led to the accumulation of toxic debris (Yablon, 2017). If such hazardous materials were not disposed of properly, then it must have accumulated in this area and thus implementing this project in this area would subject people to poisons.
Collection of undisturbed samples
Undisturbed soil samples on site might be obtained using the screw action strategy. In this method, a cutting cylinder is screwed into the soil cutting it through as guided by a guide cylinder which is mounted on a base plate. The cutting-edge rotates cutting the soil in a manner that prevents the development of shear stress. When cutting the soil core, improper use of the cutting cylinder leads to the disintegration of the soils core and hence disturbing the sample. Supply containers are required to aid transportation and handling of collected samples without interfering with the sample structure.
- Designingbuildings.co.uk. (2017). Desk study – Designing Buildings Wiki. [online] Available at: https://www.designingbuildings.co.uk/wiki/Desk_study [Accessed 14 Dec. 2017].
- GROENEWOUD, V. (n.d.). METHODS AND SAMPLERS FOR OBTAINING UNDISTURBED SOIL SAMPLES IN THE FOREST. [ebook] 272-274. Available at: http://www.cfs.nrcan.gc.ca/bookstore_pdfs/30754.pdf [Accessed 14 Dec. 2017].
- Helper, M. (2013). LAB 10: GEOLOGIC MAPS II. DETERMINING STRIKE AND DIP AND UNIT THICKNESSES FROM GEOLOGIC MAPS (pp. 12-13). Retrieved from http://www.geo.utexas.edu/courses/420k/PDF_files/LABS/gm2lab.pdf
- Scedc.caltech.edu Section, (2017). 1: What is an Earthquake?. Scedc.caltech.edu. Retrieved 14 December 2017, from http://scedc.caltech.edu/Module/s1act04.html
- Uwgb.edu. (2017). Find Strike and Dip of a Plane from Structure Contours. [online] Available at: https://www.uwgb.edu/dutchs/STRUCTGE/SL12SDFromSC.HTM [Accessed 14 Dec. 2017].
- Yablon, A. (2017). How Gun Ranges Pollute the Environment. [online] The Atlantic. Available at: https://www.theatlantic.com/politics/archive/2016/04/environmental-effects-of-guns/478803/ [Accessed 14 Dec. 2017].