Use of grouting method to improve soil bearing capacity

Soil injection is a method which used for decreasing permeability, increasing shear strength and decreasing deformations of soil. In this thesis, soil types with 40, 60, and 80% relative density are prepared for river sand and crushed stone in GP classes. Cement grout are injected to these soils at 150kPa pressure. Cement grout is prepared at 0.8, 1.0 and 1.5 of water/cement ratio. 216 soil samples are prepared by using grouting. These samples are cured in water during 7 and 28 days. After cure stage, unconfined compression tests are performed on injected samples. However, elasticity modules of samples are determined by using shear and pressure wave velocity. Maximum strength values of river sand and crushed stone samples are respectively, obtained at Dr=80%, w/c=0.8 and at Dr=60%, w/c=0.8 according to laboratory study results. In generally, river sand samples have higher strength values than crushed stone samples. Calculated elasticity modules are increased due to increasing relative density values and decreasing water/cement ratio for these injection samples. A linear relation is determined between elasticity modulus and unconfined strength values of river sand and crushed stone injection samples.