桩锚-土钉复合支护在基坑临近桥墩防护中的应用

摘要

以乌鲁木齐轨道交通2号线高铁站基坑支护方案变更为背景,梳理桩锚-土钉复合支护的受力机理和特点.运用PLAXIS分析基坑开挖周边土体变形和临近桥墩的侧移情况,定量给出桩锚-土钉复合支护的经济性分析.工程实测数据表明,桩锚-土钉复合支护可有效控制基坑侧向变形,实现对临近桥墩桩基础的保护.相对于传统围护-内支撑形式,桩锚-土钉复合支护造价低廉、可节省大量工程投资,经济效益显著.%Based on the change of foundation pit supporting scheme for Urumqi rail transit Line 2 of high-speed railway, the mechanism of combined soil nail and pile anchor are discussed.The foundation pit deformation and nearby bridge pier displacement are analyzed with PLAXIS and economic analysis of the combined soil nail and pile anchor is conducted.The results show that the new method can effectively control pit deformation and protect nearby bridge pier foundations.Compared with the traditional inner support system, it saves much investment and brings about remarkable economic benefit.