Density Test of Soil Purpose: This lab is performed to determine the in-place density of undisturbed soil obtained by pushing or drilling a thin-walled cylinder. The bulk density is the ratio of mass of moist soil to the volume of the soil sample, and the dry density is the ratio of the mass of the … Read more
How to Classify Soil Visually on site? Purpose: Visually classify the soils. Standard Reference: ASTM D 2488 – Standard Practice for Description and Identification of Soils (Visual – Manual Procedure) Significance: The first step in any geotechnical engineering project is to identify and describe the subsoil condition. For example, as soon as a ground is … Read more
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
Supervision of Brick Work Construction The following points should be kept in mind during supervision of brick work. Before using the bricks in construction it should be checked for its physical properties (such as strength, dimension, water absorption etc). Bricks must conform to the designer’s specification. Prior to use bricks in construction, it should be … 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
Field Measurements for Volume Computations Measurements for volume are nothing more than applying basic distance and elevation measurements to determine the locations and elevations of points where the volume is to be determined. It usually is not practical to take the time to collect data everywhere there is a slight change in elevation. Therefore, it … 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