Unconfined Compressive Strength Test of Soil Purpose The primary purpose of this test is to determine the unconfined compressive strength, which is then used to calculate the unconsolidated undrained shear strength of the clay under unconfined conditions. According to the ASTM standard, the unconfined compressive strength (qu) is defined as the compressive stress at which … Read more
Standard Penetration Test (SPT) Procedure Aim To perform standard penetration to obtain the penetration resistance (N-value) along the depth at a given site. Equipment & Apparatus Tripod (to give a clear height of about 4 m; one of the legs of the tripod should have ladder to facilitate a person to reach tripod head.) Tripod … Read more
Constant Head Permeability Test of Sandy Soil Purpose: The purpose of this test is to determine the permeability (hydraulic conductivity) of a sandy soil by the constant head test method. There are two general types of permeability test methods that are routinely performed in the laboratory: The constant head test method, and (2) the falling … Read more
Failure of Shallow Foundation & Preventive Measures The major causes of foundation failures are as follow Unequal settlement of sub soil Unequal settlement of masonry Presence of expansive soil below foundation Presence of mature trees Seasonal changes 1. Unequal Settlement of Sub Soil This is one of the most important reasons for foundation failure. Unequal … Read more
In geotechnical engineering, hydrometer analysis is primarily used to know the grain size distribution of a fine grained soil. In this post I will share with you the following things. What is a hydrometer? Why hydrometer analysis is done? What is the theory behind hydrometer analysis of soil? How to perform hydrometer analysis of soil? … Read more
Durability of Building Foundation A foundation is that part of the structure which is in direct contact with ground. Therefore foundations are subjected to attack by chemicals present in soil, water and by mechanical abrasion and erosion. The extent of deterioration depends on the concentration of chemicals, the level of and fluctuations in the ground … Read more
Black Cotton Soil Black cotton soil has a tendency to shrink and swell excessively. When these type of soil come in contact with water, they swell and when becomes dry, it shrinks. This alternate process of swelling and shrinking results in the differential settlement of foundation which in turn causes cracks in building. The cracks … Read more
Deciding the right depth of foundation for a building structure is an important step in the process of building design. Information given in this post will help you decide the proper depth of foundation for a building. After reading this post you will be able to answer the following questions. What is a foundation? What … Read more
PLT (Plate Load Test) Plate load test is a field test which is commonly adopted to determine the bearing capacity and settlement of soil under a given condition of loading. In this test a square or circular rigid plate of standard dimension (generally 300 mm2 for square or 300 mm dia for circular) is placed … Read more
Theory of Soil Compaction During compaction the reduction in volume is mainly due to expulsion of pore air and rearrangement of particles resulting in their closer packing. Compaction of a soil mass results in increase in dry density. The dry density attained depends on water content, amount and type of compaction. The amount and type … Read more