Structure Type Selection And Application Of Large-Caisson Transportation Wharf In Thick Soft Soil Area

At present,large caisson transportation is usually built in the terminal area of thin soft covering layer,mainly by gravity structure.In Zhongshan,a large caisson transportation terminal does not have the construction conditions of the conventional gravity structure.With the development of economy,this situation will appear more and more.The author adopts the method of theoretical analysis,field investigation and evaluation of the combination,to carry out research on thick soft soil area of large caisson transportation wharf structure selection.The main results obtained are as follows:Field survey found that,although the site geology is not suitable for the construction of gravity type wharf,but there are a large number of abandoned sand can be used as a cofferdam,the rear slightly flat to form a dry land piling conditions.Such conditions are very conducive to the construction of high piled wharf,so determine the selection of high piled wharf structure.Design the wharf to be concrete slabs without beam and concrete slabs and beam wharf.And using the finite element method to verify the theory,analysis of slope stability,structure displacement and stress etc… The analysis proves that the stability,the structure displacement and the stress of the pile foundation are satisfied with the condition of the address.Then compare the technical and economic of the selected technical scheme.Through the foundation treatment craft,the pile foundation construction craft,the wharf structure and so on cost comparison research discovery: Based on the scheme of pile foundation,the scheme can save cost by ?1,222,300;Compared to the offshore piling,dry land piling can save cost by ?390,300;Compared to the beam plate structure,the total cost of the slab structure can save ?458,100.The author also compares the two schemes of pile foundation and superstructure,the construction period of three parts of the whole project.The results show that the construction duration of each part of the slabs without beam structure is shorter than that of the slabs and beams structure.Compared to offshore piling,dry land piling can save construction period of 32 days.The upper structure and the overall duration of the wharf of concrete slabs without beam are 9 days shorter than that of the concrete slabs and beams wharf.Based on the above results,the two types of structures meet the requirements of strength,deformation and stability,and the slabs without beam structure have obvious advantages in terms of cost and duration.To this end,we choose the slabs without beam structure and put into practice.The construction monitoring period,use results show that pile wharf of the slabs without beam structure as the caisson transportation terminal is suitable in the thick soft soil.The research results have been successfully applied in two large caisson transportation wharf projects,in Zhongshan and Yangjiang.It has achieved good economic and social benefits,and has received good comments from all parties.In addition,the research results of this paper can provide reference for the design and construction of similar projects in the future.