Abstract：
A designed tunnel with a small clear distance will be constructed beneath multistoried buildings, so a numerical method was used to analyze its effects. Results indicate that the advance settlement ratio for the foundation is 13%-24% of total settlement before construction and reaches 56%-63% of total settlement before section clousure. The settlement after the clousure of the full face section of the primary support only covers 12%-24% of total settlement. The maximum ground settlement at the foundation area of the building is 16.5mm after the left and right lines pass through the nearest point and construction is finished, with a foundation local settlement of 0.0004L and inclination of 0.00042. The plastic area spreads to the earth surface during construction of the right tunnel. The above laws indicate that some cracks may occur because of the tunnel construction, which is why observation and measurement on the earth surface is essential. Meanwhile, the construction process should be optimized with a shortened closed time of the primary support in a whole section so the total settlement of the earth surface can be controlled effectively and effects on existing buildings can be minimized.
ZHAO Dong-Ping
.The Effects of Parallel Tunnel Construction with a Small Clear Distance on a Multistory Building[J] MODERN TUNNELLING TECHNOLOGY, 2011,V48(5): 30-38
2011, Vol. 48 