关键词: 盾构隧道, 下穿建筑物, 施工技术, 监测, 沉降值

Abstract:  To explore the deformation control method of the existing old residential buildings undercrossed by Wuliu avenueYaohai park shield section of phase Ⅲ project 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 0.000 8, which meet the requirements of the code design.

Key words: shield tunnel, tunneling underneath buildings; construction technology, monitoring, settlement