Study On The Behavior Of Anchored Retaining Structure Of Excavations In Soft Soil

The pile-anchor support structure is widely used in foundation pit support because it has the advantages of less influence on foundation pit excavation and more convenience on underground structure construction.However,traditional pile-anchor support is restricted in soft soil areas where the long anchor bolt can’t be used in foundation pit with the deep soft soil layer or surrounding environment.Due to the poor soil conditions in soft soil area,the ultimate friction between the anchoring section of the anchor and the surrounding land is small.This factor has a direct impact on the use of long anchors.In view of this,the anchor pier,reinforced the anchorage section of the traditional pile-anchor support with surrounding soil,and the anchor rod and the support pile together form anchored retaining structure.Not only can the anchoring force of the bolt to the supporting structure be greatly improved,the length of the anchoring section can be reduced,but also the horizontal deformation of the foundation pit can be effectively suppressed.In this paper,i will use the PLAXIS 3D software,with numerical simulation,to analyze various traits of the anchored retaining structure in soft soil foundation pit support.Its main content and results are as follows:(1)By analyzing the research and application status of traditional pile-anchor support technology in soft soil foundation,the existing problems are pointed out.(2)For the anchored retaining structure,based on the bolt cone failure model,the failure model of the anchor in the soil reinforcement zone is established and the minimum height to be set in the soil reinforcement zone is derived.(3)In this paper,the anchored retaining structure is compared with the traditional pile anchor support structure and the pile anchor support structure which enlarges the diameter of the anchorage section,and their support effect on the foundation pit in soft soil is analyzed.The results show that under the condition of controlling the same level of deformation of the retaining pile,the anchored retaining structure can effectively control the settlement of the soil outside the pit and shorten the length of the anchoring sectionof the anchor.(4)The main factors affecting the supporting effect of the anchored retaining structure are analyzed and studied in this paper.The deformation law of the anchored retaining structure is analyzed by changing the inclination angle of the anchor cable,the distance between the soil reinforcement zone and the width and depth of the soil reinforcement zone.The results show that increasing the above parameters can effectively control the deformation of the retaining pile,but the specific influence degree of each factor on the deformation of the supporting structure is different.According to the specific degree of influence of each factor,the recommended range of values for each parameter is given.(5)This paper models and analyzes the deformation law of an actual anchored retaining structure supported foundation pit engineering.The calculation results are compared with the actual monitoring data of the project,and the applicability of the anchored retaining structure in the soft soil foundation pit engineering is verified.