HOW TO IDENTIFY SILT & CLAY IN THE FIELD?

Gravel.Sand.Silt & Clay

On Site Identification of Silt & Clay The distinction between silt & clay cannot be based on particle size because the significant physical properties of the two materials are related only indirectly to the size of particles. Furthermore, since both are microscopic, physical properties other than particle size must be used as criteria for field … Read more

WHAT ARE THE DIFFERENCES BETWEEN COARSE GRAINED & FINE GRAINED SOIL?

Coarse Grained Soil vs Fine Grained Soil

Soil in an engineering sense is a relatively loose agglomerate of mineral and organic materials and sediments found above bedrock. Texturally the soil is divided into two primary groups. Coarse grained soil Fine grained soil The behavior of coarse grained soil is different from fine grained soil. The method of describing coarse grained soil is … Read more

5+ FACTORS WHICH AFFECT FIELD COMPACTION OR DEGREE OF COMPACTION

Factors Affecting Field Compaction of Soil There are many factors which influence the degree of compaction in the field. Some are compactor dependent and some depend on the soil being compacted. The factors which affect the degree of compaction are given below.  1. Type of soil Type of soil has a great influence on its … Read more

What are the requirements of bentonite (powder and suspension) used in piling work as per IS-2911

The bentonite powder and bentonite suspension used for pilling work shall satisfy the following requirements: The liquid limit of bentonite when tested in accordance with IS 2720 (Part 5) shall be 400 percent or more. The bentonite suspension shall be made by mixing it with fresh water using a pump for circulation. The density of … Read more

20 OPERATIONAL PROCEDURES WHICH MAY AFFECT THE MEASURED “N” VALUES

Blow counts are affected by operational procedures, by the presence of gravel, or cementation. They do not reflect fractures or slickensides in clay, which may be very important to strength characteristics. The standard penetration test results (N values) are influenced by operational procedures as given in the following table. No. Procedure Its Affect 1. Inadequate … Read more

Uncertainties involved in Plate Load Test

Even though plate load tests are very commonly used, they do not represent the behavior of prototype foundations totally for the following reasons: The zone of influence for prototype foundation is larger and deeper than for small size plate. Thus, in stratified soil deposits the soils at greater depths will have a significant influence on … Read more

9 PRECAUTIONS TO TAKE WHILE PERFORMING STANDARD PENETRATION TEST (SPT)

There are many pitfalls associated with the standard penetration test. If these are not carefully avoided, the N-values collected from SPT are mere numbers rather than being useful indicators of soil parameters. Some of the precautions to be taken are: Results of standard penetration test are not reproducible in cohesion less soil below water level … Read more

SLAKE DURABILITY TEST OF ROCK SAMPLE (IS-10050-1981)

Reference IS-10050-1981-Method for determination of slake durability index of rocks. Objective This test is done to find out the resistance offered by a rock sample to weakening and disintegration when subjected to two standard cycles of drying and wetting in a slaking fluid usually water. Apparatus used NAME OF EQUIPMENT CAPACITY LEAST COUNT/ACCURACY Balance As … Read more

DETERMINATION OF WATER CONTENT OF ROCK SAMPLE (IS-13030-1991)

Reference IS-13030-1991- Method of test for laboratory determination of water content, porosity, density and related properties of rock material. Objective Determination of mass of water contained in a rock sample. Apparatus used Name of equipment Capacity Least count/Accuracy Oven 105±30C 10C Balance As per requirement 0.01% of the sample   Procedure Clean the container and … Read more

UNCONFINED COMPRESSIVE STRENGTH OF ROCK SAMPLE (IS-9143-1979)

Reference IS-9143-1979-Method for the determination of unconfined compressive strength of rock materials Objective The objective of this test is to determine unconfined compressive strength of rock. This test is primarily done to classify the rock on the basis of strength. Apparatus used Name of equipment Capacity Least count/Accuracy Loading Machine 5000 kN 2.5 N Vernier … Read more