Design And Construction Of Deep Foundation Pit Supporting In Tianjin Area

In the process of urban construction,as a result of increasing population density,land utilization,and the environment surrounding the foundation pit engineering is often very complicated.The foundation soil is generally made up of a thick layer of loose sediments in the fourth quarter,such as artificial soil and clay layer,silt,silty clay layer,gravel layer,muddy soil,sand,etc.,these loose materials constitute the soil when the foundation pit excavation,from its steady height is limited.Groundwater depth is shallow,water pressure acting on retaining structure,the lateral deformation of retaining structure has a great influence,if not to effectively prevent,happen,sand flow,the phenomenon such as a sudden surge of piping were greatly improved,the possibility of increasing the instability and failure of foundation pit.In the course of construction,the effects of deep foundation pit engineering as well as there are too many uncertainty factors,from the current circumstances in the engineering practice than the relevant theoretical research results more conducive to the development of the project construction,many projects are now through construction experience to determine the concrete scheme of deep foundation pit engineering construction,but this way of handling a lot of problems,although there are many building designers are on support technology of deep foundation pit engineering carried out extensive research,has a large number of experiments to determine the reliability of the supporting schemes,but still in the process of practical application of the safety accident will happen.In the construction industry rapid development stage,how to guarantee the construction progress,project quality and construction safety is the problem that the industry needs to think about,and one of the choice of foundation pit supporting scheme is one of the very important work,the choice of reasonable support scheme can not only save construction cost as much as possible,can also reduce the probability of safety accidents.In this paper,in view of the deep foundation pit construction process and the dynamic construction of deep foundation pit numerical studies these two aspects of content.There are two main types of research methods,the first is for deep foundation pit monitoring of parameters related to the construction site,the second is the finite element analysis method.Combine the two methods in the process of analysis to determine the deep foundation pit engineering construction internal stress and displacement of foundation pit retaining structure and foundation rock mass and other parameters.The author analyzes a large amount of data processing after come to the conclusion that if the project in the foundation pit stability factor greater than 2 indicates the stability performance of the foundation pit is relatively good;Cause displacement is due to the soil by excavation of foundation pit,and will make the foundation pit for foundation pit excavation of stress index changes: the applicable scope of the various kinds of supporting structure is different,so can not simply judge of the supporting technology,at present a lot of construction steel pipe pile + the anchor supporting units,its main function is to reduce the foundation pit displacement values.When making the soil excavation need according to the structure characteristics of the soil and construction units have technology to the choice of reasonable support scheme and makes supporting scheme of diversification as far as possible,so that can improve the stability of foundation pit.