Presentation of Geotechnical Investigation Report Upon completion of the geotechnical investigation and analysis, the information and findings must be compiled in a standard report format. The report serves as the permanent record of all geotechnical data known to be pertinent to the project and is referred to throughout the design, construction, and service life of … Read more
SOIL STRUCTURE / SOIL FABRIC The term soil structure in general, refers to the arrangement or state of aggregation of particles in a soil mass. But deeper understanding of soil structure demands consideration of mineralogical composition, shape and orientation of soil particles; the nature and properties of soil water, and the forces of interaction between … Read more
Depth and Spacing of Trial Pits & Borings The depth and spacing of trial pits or exploratory borings should be such as to give a true picture of the underlying soil, with regard to any major changes in thickness, depth or properties of the strata over the base area of the structure and in its … Read more
Values of Safe Bearing Capacity The safe bearing capacity of soil should be determined on the basis of soil test data or by performing some field test such as Standard penetration test or Plate load test etc. However, in the absence of soil test data, the values of safe bearing capacity (S.B.C) as given in … Read more
On-Site Identification & Classification of Soil The principle terms used by civil engineers to describe soils are Gravel (particle size larger than 4.75 mm) Sand (particle size within 4.75 mm to 0.075mm) Silt & Clay (particle size less than 0.075mm) Most natural soils consist of a mixture of two or more of these constituents and … Read more
Electrical Resistivity Test of Soil This method depends on differences in the electrical resistance of different soil (and rock) types. The flow of current through a soil is mainly due to electrolytic action and therefore depends on the concentration of dissolved salts in the pores. The mineral particles of soil are poor conductors of current. … Read more
Step-by-Step Procedure for Calculation of Bearing Capacity from Standard Penetration Test Values or N-values Step-1 Perform standard penetration test on the location for which you want to calculate bearing capacity. This is done as per standard procedure given in IS-2131. Standard penetration test must be done at every 75 cm in vertical direction. Step-2 Decide … Read more
Carbonation of Concrete Carbonation of concrete is one of the reasons for corrosion of reinforcement. It is a process by which carbon dioxide from air penetrates into the concrete and reacts with calcium hydroxide to form calcium carbonates. The percentage of CO2 present is air vary from place to place. In case of rural areas … Read more
Objective To perform plate load test to obtain a load-settlement curve of a soil at a particular depth so as to estimate the ultimate bearing capacity a foundation. Apparatus Test plate of square size (300 mm or 450 mm or 600 mm or 750 mm) Hydraulic jack (50 T capacity) Hydraulic pump (50 T capacity) … Read more
This simple and quick field test will give you a rough idea of bearing capacity of soil. Procedure Excavate a pit of required depth. (preferably equal to the depth of foundation) Take a solid ball or square cube of known weight and dimension. Drop the ball or square cube several times, from a known height … Read more