Influence of Construction Sequence and Different Types of Pipes on Ground Surface Settlement Caused by the Construction of Two-layer Jacking-pipes
(1 Guangzhou Municipal Engineering Group Co., Ltd., Guangzhou 510060; 2 Municipal Engineering Technology Research Institute,Guangzhou Municipal Engineering Group Co. Ltd., Guangzhou 510060)
Abstract:
Aiming at the ground surface settlement caused by two-layer jacking-pipes construction and its influen? tial factors, a three-dimensional model was established by finite element software to simulate and calculate pipejacking construction under considering interaction of bulkhead pressure, ground loss and grouting, to discuss the impact of construction sequence and pipe type on ground surface settlement. The results show that the maximum settlement caused by two-layer jacking-pipes construction occurs on the upper side of the lower jacking pipe and it reduces by 17.84% with the excavation of upper jacking-pipe, and the heaving at lower side barely changes; the main affected area of ground surface settlement is within the scope of - 3.2D1~3.2D1 around the jacking-pipe axis; the maximum ground surface settlement caused by the antecedent construction of the lower jacking-pipe occupies 78.05% of the total settlement; subsequent excavation of the upper jacking-pipe results in obvious heaving in front of it, the total settlement decreases and ground surface settlement increases after passing of jacking-pipe head, the maximum settlement increases by 21.95%, the increasing and attenuation rates of ground heaving both reduce with the advance of jacking-pipe; the ground surface settlement caused by the precedent construction of the upper-layer jacking-pipe increases largely by 20.5% compared with that of precedent construction of the lower-layer jackingpipe; the ground surface settlement caused by concrete jacking-pipe is larger than that of steel jacking-pipe, the maximum settlement increases by 26.13% and the affected scope increases to -4.8D1~4.8D1.
AN Guanfeng1,
2 WANG Tan1,
2 SI Haifeng1 etc
.Influence of Construction Sequence and Different Types of Pipes on Ground Surface Settlement Caused by the Construction of Two-layer Jacking-pipes[J] MODERN TUNNELLING TECHNOLOGY, 2019,V56(4): 119-126