Earth Excavation Checklist The following checklist should be used as a guide for better quality control over earth excavation. (1) Prior to the start of excavation operations, take photographs of the construction area, make sure that sufficient cross—sections are taken, and continue to take progress photographs during construction. (2) Review the log of borings to … Read more
Shear Strength Test of Soil The choice of appropriate shear strength tests for a particular project depends on the soil type, whether the parameters will be used in a total or effective stress analysis, and the relative importance of the structure. Common laboratory tests include direct shear, triaxial, unconfined compression, and laboratory vane shear test. … Read more
Types of Soil Shear Test Based on Drainage Condition The shear strength parameters in the case of saturated soils depend very much upon the drainage conditions and therefore in the laboratory shear test, the drainage condition expected in the field for a particular problem should be simulated. Based on drainage condition the shear tests are … Read more
Measurement of Soil Compaction in the Field It is necessary in many instances to know the wet/dry densities of the soil in the field, especially before planning activities such as compaction. The same becomes particularly important in instances such as the construction of earth dams, embankments etc. to control the field compaction, that is, to … Read more
Determination of Organic Matter in Soil Purpose: This test is performed to determine the organic content of soils. The organic content is the ratio, expressed as a percentage, of the mass of organic matter in a given mass of soil to the mass of the dry soil solids. Standard Reference: ASTM D 2974 – Standard … Read more
Relative Density or Density Index Test of Sand Purpose: This lab is performed to determine the relative density of cohesionless, free-draining soils using a vibrating table. The relative density of a soil is the ratio, expressed as a percentage, of the difference between the maximum index void ratio and the field void ratio of a … Read more
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