Conventional deep excavation support systems (diaphragm wall with inner strut) have fixed length of struts, which can lead to a significant discrepancy between deformations of actual and designed diaphragm wall systems. As a result, failure of support system is likely to occur during the deep excavation. In this paper, a novel deep excavation support system with adjustable strut length was proposed, whereby the construction risk during deep excavation can be effectively reduced. An intelligent adjustment method of coordinated deformation of deep excavation support system was proposed as well. Model tests were carried out to investigate the influence of inner strut length on the mechanical and deformation characteristics of the system consisting of inner strut, diaphragm wall and soil behind diaphragm wall. The inner strut forces, lateral earth pressure on the diaphragm wall, the ground settlement and the deformation of the diaphragm wall were measured and analyzed. Results show that control the horizontal displacement of the braced excavation strictly will lead to the increment of axial force and the axial compression ratio of strut, which pose a threat to the safety of the strut system. By contrast, a reasonable adjusted length of inner strut is favorable to the safety of construction.

传统的深基坑支护系统（带有内撑杆的连续墙）具有固定长度的撑杆，这会导致实际和设计的连续墙系统变形之间存在显着差异。因此，在深基坑开挖过程中很可能发生支护系统故障。本文提出了一种新型的支杆长度可调的深基坑支护系统，有效降低了深基坑施工过程中的施工风险。提出了一种深基坑支护系统协调变形智能调整方法。通过模型试验研究了内撑杆长度对内撑杆、连续墙和连续墙后土组成的体系力学和变形特性的影响。内在的支撑力，对连续墙的侧向土压力、地面沉降和连续墙的变形进行了测量和分析。结果表明，严格控制支护基坑的水平位移会导致支杆轴力和轴压比增大，对支杆系统的安全构成威胁。相比之下，合理调整内撑杆长度有利于施工安全。