Study On New Technologies For Cofferdam Filling And Foundation Pit Supporting Of Sha Jing Sliuce

Weak claypan is widely distributed in coastal areas of China, which lies in the deepunderground. Its engineering characteristics are high water content and compressibility, lowshear strength and permeability. Water conservancy projects on claypan such as sluices andpump stations, the cofferdam filling and foundation pit supporting are often the focus anddifficult points of the engineering design, which have many problems to be researched.Based on the project of Sha Jing Sluice in Shenzhen, the thesis makes a theoreticalanalysis of the new technologies for the cofferdam filling and foundation pit supporting on thedeep silt foundation. The project is located on the intersection of Sha Jing River and MaoZhou River. It is the paralic soft soil foundation, which is covered with deep silt. As the slithas poor shear strength and low bearing capacity, in order to meet the requirements of stability,economy and construction period, a new technology of consolidation is used, which iscombined with the technology reinforced earth. In addition, the slit can’t keep stability itself,to control the adverse deformations, a new technology of cement-soil pile retaining wall is putforward, which uses the large diameter stirring pile technology.In allusion to the feasibility of these new technologies, studies have been done andconclusions have been obtained as follows.Firstly, by calculating the consolidation settlement and slope stability, the paper aims toillustrate the advantages of sand quilt. The consolidation of the sludge is accelerated, thefoundation soil shear strength and the overall stability of the cofferdam are also improved, andthe overall load time is shorten.Secondly, based on the study on the effect of large diameter mixing pile retaining wall,the advantages of this new technolog are illustrated. Analyzed by numerical simulation, theeffect of large diameter mixing pile retaining wall in this foundation pit project is researched.And by analyzing the effect of strength and stiffness of cement-soil pile retaining wall on thepit traits, conclusions can be reached that large diameter stirring pile retaining wall withsimilar-rigid strength can reduce the soil settlement, avoid horizontal displacement of theretaining wall and the blow ups of the pit bottom, which therefore illustrates the engineeringand technical advantages of this technology used in cement-soil retaining wall foundation.