盾构下穿砖混民房建筑群施工控制技术研究——以合肥轨道交通1号线三期工程为例

Construction Control Technology of Shield Tunneling underneath Brick-and-Concrete Residential Buildings:a Case Study of Phase Ⅲ Project of Hefei Rail Transit Line 1

为研究已产生一定变形的老旧民房的变形控制方法,以合肥轨道交通1号线三期工程物流大道站—瑶海公园站区间盾构穿越砖混民房建筑群为例,提出变形余量的确定方法,以及综合考虑边界、时间、空间3要素的变形控制方法。通过民房安全评估,以局部倾斜为主控因素确定施工变形控制指标及施工控制要点;采用工程类比法在地质条件和周边环境相似的试验段研究施工控制方案优化,验证降低背后回填浆液初凝时间、及时补充浆液、采用矮小型刮刀且超挖刀收缩的方式掘进对变形控制的有效性。将试验段优化方案应用于下穿民房施工段,实测数据表明,民房最大变形沉降为6.48 mm,最大局部倾斜为0.0008,满足规范设计要求。

To explore the deformation control method of the existing old residential buildings undercrossed by Wuliu avenue-Yaohai park shield section of phaseⅢproject of Hefei metro line 1,the determination method of allowable deformation and the deformation control method considering the boundary,time,and space are put forward.The construction control indexes are proposed through the safety assessment of residential buildings according to local tilt.Then,the engineering analogy method is used to conduct field test study in the test section where the geological conditions and the surrounding environment are similar.The optimal scheme of reducing the initial setting time of backfill grout,injecting second serous in time,adopting short scraper,and over-cut cutter shrinkage driving is proven to be effective to reduce the length of open space.The construction tunneling parameters are summed up and applied to the construction section under the residential buildings.The monitoring results show that the maximum deformation settlement is 6.48 mm and the maximum local inclination is 0.0008,which meet the requirements of the code design.