Abstract：
A risk assessment and corresponding treatment are carried out for the special working conditions regarding shield tunnelling under houses for the Wuxi Metro Line 1(from the College town station to the Xuelang station). There are two problems that need to be solved: 1) the passage under the houses, for which the earth pressure intensity shall be calculated and backfilling shall be adopted for the deep well, which may breakdown under the grouting pressure; and 2) maintaining construction safety during tunnelling under the old houses, whose foundational structures, service conditions, safety performance and controllable settlement shall be investigated and evaluated. For these problems, such construction countermeasures as uniform and continual shield driving, less correction of alignment deviation and regular monitoring are presented. The results show that these countermeasures are feasible and appropriate for the requirements of construction safety, including calculation of earth pressure intensity, control of shield tunnelling parameters, shield attitude adjustment and monitoring and measurement; when the shield passed beneath the houses, no danger occurred and the maximum settlement was 8.2 mm.
2015, Vol. 52 