The Study On Bearing Properties Of Oblique Churning Mixing Reinforced Cement Soil Anchors Of Soft Soil Deep Excavation Pits

In recent years the safety accidents of soft soil deep excavation pits occurred frequently and caused serious harm, especially in the area of soft soil where mechanics performance is poor,then the traditional technology of protecting the structure is put forward new needs.The pullout force which ordinary anchors provide has been far from supplying the requirements for deep and large-scale silt.This problem was solved by increasing the number of cables or cable length in the traditional method,which would lead to economic cost or beyond the red line.The oblique churning mixing reinforced cement soil anchors improve the performance of the anchored soil and increase the radius of anchored solid and ultimate pullout force,what’s more they reduce the cable length and the cost in view of the above defects,which are widely used for protecting the structure of soft soil. At present the structure design on oblique churning mixing reinforced cement soil anchors is according to the construction experience,so how to determine theoretically ultimate pullout force has an important guiding significance.Based on the oblique churning mixing reinforced cement soil anchors of deep excavation pits in Foshan Nanhai Wanda Plaza among the Pearl River Delta region,the mechanics method on bearing mechanism and ultimate pullout force of anchors is be discussed according to theoretical analysis, numerical simulation and field monitoring combinationDeducing the analytical solution of ultimate pullout force based on modern theory of soil mechanics and simplified mechanical model of oblique churning mixing reinforced cement soil anchors.Based on the FEM analysis software of Midas GTS,using mohr-coulomb yielding criteria,establishing the simulation model of oblique churning mixing reinforced cement soil anchors,analysing the impact of the scope of consolidation and other factors such as soil parameters and cement mixing ratio for ultimate pullout force,obtaining bearing characteristics. By monitoring oblique churning mixing reinforced cement soil anchors of deep excavation pits in Foshan Nanhai Wanda Plaza,the change curves of deep horizontal displacement of retaining structure,retaining structure horizontal displacement at the top and reinforced anchorage force are obtained for providing true and reliable data for the research work.Finally according to comparative analysis of the theoretical calculation formula on ultimate pullout force,the FEM analysis and the results of the field test which are applied to engineering practice, validating rationality of the analysis method,and putting forward related suggestions on the design of oblique churning mixing reinforced cement soil anchors of deep excavation pits.