摘要
新建隧道施工对近接隧道的影响,一直是隧道设计和施工中必须考虑的问题,但现阶段对此还没有一致的认识。为了进一步研究新建隧道施工对近接隧道影响机理,设计了能够模拟隧道分步开挖的室内模型试验装置,并用该试验装置进行了砂土地层中新建隧道施工引起近接水平平行隧道位移的试验研究。试验重点研究了两平行隧道间净距、埋深对既有隧道位移的影响。通过对试验结果分析,得到了既有隧道拱顶和靠近新建隧道一侧拱腰部位的位移发展规律。试验结果分析表明,新建隧道开挖会对既有平行隧道结构产生侧向挤压效应,隧道埋深和净距对既有隧道的位移都有影响,但隧道间净距变化对位移量的影响更大。当隧道间净距大于2倍隧道直径时,新建隧道开挖对既有水平平行隧道位移的影响非常小。研究成果可为砂土地层中近距离平行隧道设计和施工提供参考。
The influences of new tunnel excavation on adjacent tunnel have always been a must consideration in the design and construction of tunnel, but there are no common concessions on this issue. For a better understanding the mechanism of the influence of new tunnel construction on the adjacent one, a laboratory model test system, which can be used to simulate the step-by-step tunnel excavation, has been designed. With the designed model test system, a series of laboratory model tests were carried out to investigate displacements of the existing horizontal parallel tunnel induced by the excavation of new tunnel in sandy soil. Special attention was paid to the influence of tunnel cover depth and separating distance between two tunnels on displacements of the existing tunnel during the new tunnel exca- vation. Based on the analysis of test results under different separating distance and tunnel cover depth, the develop- ment rule of the displacements of the crown and springline at the side of existing tunnel near to the new tunnel was i- dentified. It shows that the existing tunnel is under lateral extrusion during horizontal parallel tunnel excavation, and the tunnel cover depth and separating distance between two tunnels all have influence on the displacements, hut the latter effect on the magnitude of displacements is more significant than the former. When the separating distance is larger than two times the tunnel diameter, the new tunnel excavation has very small effects on the displacements of the existing horizontal parallel tunnel. Such findings can serve as a reference for the design and construction of closely spaced parallel tunnels in sandy soil.
出处
《地下空间与工程学报》
CSCD
北大核心
2014年第2期270-275,共6页
Chinese Journal of Underground Space and Engineering
基金
住房和城乡建设部科技资助项目(2011-K3-28)
关键词
模型试验
既有隧道
近接隧道施工
位移
model test
existing tunnel
adjacent tunnel construction
displacement
