The Study On Foundation Treatment And Settlement Prediction Of Marine Deposits Soft Soil

Seashore soft soil is widely distributed in the southeast coastal area of China.The kind of soft soil has high water content,low strength,high compressibility and poor permeability.If the road is built on this kind of soft soil,including highway,railway and so on,serious cracks,uneven settlement and other serious engineering accidents will happen possibly.Especially for the large area of deep soft soil,foundation treatment result will affect the project progress,investment and quality.So aimed at the project,the corresponding site test or construction test section should be carried out,making different ground treatment,and the treatment results were compared and analyzed to get the best methods of reinforcement,which will provide guidance for construction for the following.A port of FUJIAN province,is located in the coastal beach land.Geological survey report shows that there is littoral facies soft soil below the surface.Due to the expansion of the site and road,the foundation reinforcement is needed.Therefore,based on the background of the enginering of soft soil foundation treatment,combined with the site environment,this paper made six kinds of foundation treatment scheme.Through field test,field monitoring,in-situ test and indoor test,the quality difference between different treatment scheme can be getted.Finally,the method of numerical simulation of FLAC3D combined with neural network is used to predict the post construction settlement of the foundation during operation.For this reason,the following works are done in this paper:(1)According to the overall goal of the project quality,we should first set up the test sections.Considering the protection zone and subgrade district,the test is divided into three test sections in respective regions,a total of six different soft foundation treatment schemes.During the test monitoring progres,the settlement laws of the foundation based on different treatment schemes are obtained,which provide the basis for schemes comparison in later period.(2)In order to analyze the effect of different treatment schemes,we carry out the original testing research,including vane shear test and static cone penetration test,to get the change rule about the carrying capacity and the strength of foundation before and after treatment.The soil mechanical parameters before and after treatment are obtained by boring sampling and laboratory soil test,which provide the basis for the prediction of the settlement.(3)This paper mainly analyzes the most representative three schemes of consolidation treatment of foundation drainage which correspond to the 2 test section(drain preloading)?test section 3(the vacuum drainage board)and test section 6(preloading and sand pile preloading).Based on the observed data,combined with in situ testing and laboratory test results,we estimated the foundation settlement during the treatment and forecasted post-construction settlement by using the method of numerical simulation of FLAC3D combined with neural network.