严寒地区超期超深基坑检测及治理技术

Comprehensive Construction Technology of Monitoring and Control of Overage Extended-used Ultra-deep Foundation Excavation in Severe Cold Area

超深基坑支护是基坑工程的关键工序之一,尤其在北方严寒地区,超深基坑工程多数为跨年度越冬工程,基坑支护结构本身及其锚固土体易受冻融作用影响,冻融前后支护结构及土体的物理、力学性质变化造成深基坑边坡失稳,导致基坑工程事故发生。在基坑外侧的土体,由于冻渗的作用产生融沉现象。为保证基坑的安全稳定性,越冬后需对基坑的安全性进行评估,采取适当加固措施。

Ultra-deep foundation excavation is one of the key process engineering,especially in cold northern regions, the majority of ultra-deep foundation excavation are winter multi-year project,foundation excavation and anchoring the soil structure itself are vulnerable to freezing and thawing effect of physical structure and support before and after freezing and thawing of the soil,caused by changes in the mechanical properties of deep foundation excavation slope instability, which leads to frequent accidents excavation. In the soil pit outside,frost penetration causes thawing settlement phenomenon. To ensure the safety and stability of foundation excavation,after wintering,the safety of foundation excavation needs to be evaluated,appropriate reinforcement measures are taken.