Assessment of rapid impact compaction in ground improvement from in-situ testing

M. M. Mohammed, H. Roslan, S. Firas

(Department of Civil Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur 50603, Malaysia)

Abstract:Ground improvement has been used on many construction sites to densify granular materials, in other word, to improve soil properties and reduce potential settlement. This work presents a case study of ground improvement using rapid impact compaction (RIC). The research site comprises the construction of workshop and depots as part of railway development project at Batu Gajah-Ipoh, Malaysia. In-situ testing results show that the subsurface soil comprises mainly of sand and silty sand through the investigated depth extended to 10 m. Groundwater is approximately 0.5 m below the ground surface. Evaluation of improvement was based on the results of pre- and post-improvement cone penetration test (CPT). Interpretation software has been used to infer soil properties. Load test was conducted to estimate soil settlement. It is found that the technique succeeds in improving soil properties namely the relative density increases from 45% to 70%, the friction angle of soil is increased by an average of 3^o, and the soil settlement is reduced by 50%. The technique succeeds in improving soil properties to approximately 5.0 m in depth depending on soil uniformity with depth.

Key words:cone penetration test; granular soil; compaction; rapid impact compaction; relative density; settlement; improvement depth; in-situ testing