Abstract：The interference of axial force between prestressed steel struts in foundation pit(axial force interference) is an important factor affecting the axial force control of struts. In order to overcome the axial force loss of struts caused by the coherence of axial force,this paper relies on a deep excavation project in Shanghai and uses numerical simulation and realtime monitoring to study the coherence of support axial force and deformation characteristics of retaining wall under multipoint synchronous loading. A comparative analysis with ordinary individually loading method is also presented. The results indicate that that under ordinary individual loading,the axial force loss of the adjacent struts increases with the applied pre-stress of new mounting strut,but decreases sharply with the distance. When the distance exceeds 8 m,the axial force loss of adjacent struts is near zero,an axial force coherence estimation formula is obtained according to these laws. Different from loading struts individually,although the multi-point synchronous loading causes larger axial force loss of the adjacent struts outside of the loading zone,the influence scope basically remains unchanged,and the struts loaded synchronously have almost no mutual influence. The axial force loss rate for more than 95% of the struts is less than 5%. Under multi-point synchronous loading,the deflection of the retaining wall (27～40 mm) is not only smaller than the normal ones,but also distributes more evenly along the longitudinal direction of the foundation pit (σ2=0.99).
何君佐 廖少明 孙九春 唐俊华. 软土深基坑钢支撑多点同步加载的轴力相干性研究[J]. 土木工程学报, 2020, 53(7): 99-107.
He Junzuo Liao Shaoming Sun Jiuchun Tang Junhua. Study on axial force interference of soft soil deep excavation#br#
under multi-point synchronous loading. 土木工程学报, 2020, 53(7): 99-107.
