Soil stabilization deals with physical, physicochemical and chemical methods to make the stabilized soil serve its purpose as pavement component material.
Bearing capacity of cohesive soils The ultimate bearing capacity of saturated cohesive soils (clay and silt) with low permeability is most critical immediately after construction, before the excess porewater pressure has had time to dissipate i.e. undrained conditions. As time proceeds, consolidation occurs, the soil becomes stiffer and has more strength. Therefore design of foundations(…)
Types of shear failure of foundation soils: Depending on the stiffness of foundation soil and depth of foundation, the following are the modes of shear failure experienced by the foundation soil. 1. General shear failure (Fig.1(a)) 2. Local shear failure (Fig.1(b)) 3. Punching shear failure (Fig.1(c)) Fig.1: Shear failure in foundation soil Fig: Curve in(…)
Bearing capacity of soils are reduced by a factor called factor of Safety to underestimate the bearing capacity of soils. This value of factor of safety depends on following factors: 1. Type of soil 2. Method of exploration 3. Level of Uncertainty in Soil Strength 4. Importance of structure and consequences of failure 5. Likelihood(…)
Compaction of soils required for different types materials for embankment and subgrade are shown here based on IS:2720 – part-8. Following table shows the relative compaction for different soil types: Sl. No. Type of work / material Relative compaction as percentage of maximum laboratory dry density 1 Subgrade and earthen shoulders Not more than 97(…)
Soil Classification for Purpose of Measurement and Payment All materials to be excavated is classified into one of the following classes and is paid for at the rate for that particular class of material. No distinction is made whether the material is dry, moist or wet. Any earthwork is classified under any of the following(…)
Dynamic probe test is done to determine the penetration resistance of soil. Apparatus required for dynamic probe test of soil are: (a) Dynamic Probe: The anvils shall be rigidly fixed to the guide rod; the lower anvil shall also be rigidly fixed to the extension rods. The mass of the lower anvil shall be 1.5(…)
Earthwork in excavation upto required depth is required for construction of foundation. It is a very important part of construction process, and care must be taken while excavation in safety perspective. Different soil layers may be encountered while excavation, dewatering may be needed sometimes. These points must be kept in mind to take necessary action(…)