Experinces with Soft Clay Improvement in the Bangkok plain

This lecture summarizes the progress of the development of the different ground improvement techniques in Bangkok Plain and is reviewed in relation to the extensive deep wen pumping and the resulting piezometric drawdown at deeper depths. Case records of test embankments with sand drains, sand wicks and PVD are presented to inustrate the effectiveness of different types of vertical drains with surcharge. The use of prefsbicated drain seems more superior than the other types of sand drain. Construction of test embaxlkment, criteria for PVD selection and relevant laboratory testing techniques are discussed for formulating the specif'ication. Alternative teckuuque, such in, the use of deep chemical mixing is reviewed in terms of the efficiency of cement, lime and flyash as additive. Vacuum pre-loading with surcharge and elctro- osmotic consolidation are also explored as possible tectmiques to improve the engineering properties of soft Bangkok clay.