穿越旧城区地下障碍的深基坑支护结构施工技术研究

Research on Construction Technology of Deep Foundation Pit Supporting Structure Passing through Underground Obstacles in Old City

针对旧城区拆除旧建筑作业时易于形成较厚且松散的杂填土层,不利于形成泥浆护壁、穿越旧底板障碍成桩施工难、无法直接形成止水帷幕等问题,提出了一种穿越旧城区地下障碍的深基坑支护结构施工技术。通过多功能钻机直接驱动切削靴套筒快速钻进底板顶部,然后更换钻头穿越障碍、调整泥浆配比进行灌注桩施工,利用地质钻机引孔形成“高压旋喷-既有地下室底板-高压旋喷”的止水帷幕体系,并在施工过程中辅以基于区块链的深基坑智能监控集成平台,实时监控施工过程中周边老旧建筑的倾斜、位移变形量,确保深基坑土方开挖时的施工安全。

Aiming at the problems of thick and loose miscellaneous filling soil formation during the demolition of old buildings in the old city,it is not conducive to the formation of mud protection wall,the difficulty of pile construction through the old floor barrier,and the inability to directly form a water-stop curtain.Construction technology of deep foundation pit supporting structure for underground barriers in urban areas.The cutting shoe sleeve is directly driven by a multifunctional drilling rig to quickly drill into the top of the bottom plate,then the drill bit is replaced to cross the obstacles,the mud ratio is adjusted to carry out the construction of the cast-in-place pile,and the geological drilling rig is used to form the“high pressure jet grouting-existing basement floor-high pressure jet grouting”.Water-stop curtain system,supplemented by a blockchain-based intelligent monitoring integrated platform for deep foundation pits during the construction process,real-time monitoring of the inclination,displacement and deformation of the surrounding old buildings during the construction process to ensure the excavation of the deep foundation pit timely construction safety.