A New Technique of Reinforcing Soft Cohesive Ground by Deep Mixing Method

The technique of deep mixing method is used to reinforcing soft cohesive ground,in which cement is used as a consolidating agent and a special deep mixing machine is utilized. The purpose of this technique is to increase the strength of the soil in a considerable depth by injecting cement slurry and by mixing of the cement slurry with the soil. Compared with the untreated soil,soil consolidated by this method has a compressive strength 40-100 times higher.This method is suitable for reinforcing the soft cohesive ground,particularly the very soft clay.This paper introduces cardinal parts of the aforesaid technique: ①laboratory studies, ②research for deep mixing machine, ③in-situ experiments and applications of this technique to foundation engineering.Technical appraisement concluded that the dispansation of the consolidation agent, the deep mixing machine SJB-1,and the associated technology of the job basically have formed a system of deep mixing method on land suitable to our country. It offers a new method in the field of cohesive ground reinforcement,and will extend with a wider application in soft cohesive ground inprovement progressively.