Deformation Law And Numerical Model Analysis Of A Deep Foundation Pit Supporting Structure In Guangzhou

With the expansion of the city scale,the contradiction between the rapid development of urban engineering construction and tense land resources is also growing.In order to alleviate this contradiction,more and more deep foundation pits have emerged.With the deepening of the depth of foundation pits in the project construction,the deformation regularity,mechanism,and support methods for excavation during the excavation process have become very important.Guangzhou is a large-scale central city in the south of China.The number of construction projects is huge.However,Guangzhou has a variety of rock formations,and the engineering characteristics of different strata are not the same.Therefore,various types of construction are encountered during the excavation of deep foundation pits.Engineering and environmental geology issues such as large deformation,gushing water,and ground subsidence.This paper takes the composite support structure of pile-anchor and pile-support of a deep excavation engineering in Guangzhou as the research object,and uses the combination of field monitoring and finite element software Midas gts NX simulation to study the process of excavation in the foundation pit.Protection structure deformation,anchor cable stress,and the variation of internal support axial force will accumulate experience for other similar projects in the region in the future.Obtained the following research knowledge:(1)The support scheme for the deep excavation using the pile piles+two internal supports+ one row of anchor cables and row piles+4 rows of anchor cables has not reached the alert value in the monitoring results,indicating that the supporting plan can effectively limit Deformation of foundation pits and proper selection of foundation pit support.(2)During the excavation process of the foundation pit,the vertical displacement of the top of the retaining pile is related to whether the lower soil layer and supporting structure are applied;the horizontal deformation and excavation depth of the retaining pile and the anchor cable and the inner With regard to the position of the support,the maximum lateral displacement gradually decreases as the depth of excavation increases,showing a bulging tendency and the inside of the pit.(3)Compared with the actual measurement results,the deformation characteristics of the support structure obtained by finite element numerical simulation are the same in the overall trend,indicating that the numerical simulation has certain reference value,and the finite element software helps the theoretical analysis of the foundation pit support design.