Geotechnical Design Assessment of Flyover and Underpass at Link Road M2/M1 (P-0984) (MFN 5932)

Abstract

The objective of the study is to carry out geotechnical design assessment of flyover and underpass at link road M2/M1, Islamabad. The study area lies south west of Islamabad, near New International Islamabad Airport (NIIA).Two boreholes have been drilled by percussion drilling method. Both disturbed and undisturbed soil samples were considered in terms of the proper handling, transportation, and storage of soil samples for laboratory testing. The tests conducted in the laboratory on these soil samples includegrain size distribution, Atterberg limits, shear strength, and unconfined compressive strength. Hence, the parameters calculated include particle size, liquid limit, plastic limit, plasticity index, angle of friction, cohesion and maximum compressive strength. Along with tests conducted in the laboratory, different parameters were also determined in the field. These includebulk density, in-situ moisture content and standard penetration test. Geotechnical interpretations were made by correlating these soil strength parameters acquired from both the field and lab for determining the engineering properties of the soil. Furthermore, the allowable bearing capacity for single pile against its length was determined. These calculations were carried out for pile diameters of 0.75, 1.0, 1.2 and 1.5m. The measurements were made using the values obtained from the standard penetration tests. The values of allowable load for the fraction piles varies from 85.79-103.3 tons by keeping the diameter 1.2 m and embedded length of the pile 30.0 m.The most appropriate foundation for site location is pile foundation. This foundation was chosen to compensate for atmospheric pressure applied on the foundations