In-situ Measurement Study On Deformation And Internal Force Of Pile-anchor Retaining Excavation

With the rapid development of urban construction in Jinan,a large number of high-rise buildings are appearing and many deep excavations are increased gradually. According to the incomplete statistics, a lot of pit collapse accidents have happened during these years. The main reasons for these cases are short of knowledge of the retaining structure during excavation, and they can’t forecast the danger and couldn’t take the appropriate measures to deal with the accidents.Jinan are now preparing for the subway construction while the substantive matters have been carried out. In order to understand exact retaining structure in the variation of the internal force and displacement, Green Center is for the background in this article. With the analysis of the monitoring and construction data, the general rules of the deformation of retaining structure are summarized in the region. The impact on the surrounding environment in pit excavation is analyzed, especially buildings, pipelines and roads when some relative deformation factors are analyzed comparatively. Several parts are included in this article as follows:(1)Deep excavation itself is a complicated systematic project.During excavation,deformation and stress in the envelope structure will be changed with the diversification in the time and space.The excavation deformation mechanism is analyzed theoretically.And many effective measures are given to control the deformation of the pit.(2) Controlling the deformation of the retaining structure and surrounding environment has become a key technology in the construction.In the base of the monitoring data, the laws of displacements and internal forces in piles, deep soil horizontal displacement, the ring beam horizontal and vertical displacement, deformation of the pipelines and settlement of the surrounding buildings are discussed.(3) The research of the deformation in foundation pit structures is fragmented.In order to have a better understanding of the pit support, the article studies the mutual relations in the surface subsidence and the pile displacement,the cable tension and the pile displacement, building settlement and pit excavation with precipitation.(4) On the basis of bracing,there are many specific analysis with the depth of the supporting piles, anchor applied, buildings around pit and other factors. The theoretical basis is calculated in Lizheng software by seizing the key conditions,which are compared with the monitoring data.