基坑局部堆载回压对下卧隧道隆起影响  

Impact of Foundation Pit Local Heaped Load on the Uplift of the Underlying Tunnel

作　　者：肖勇卓 刘刚 Xiao Yongzhuo;Liu Gang(School of Mechanics and Civil Engineering,China University of Mining and Technology,Xuzhou 221116,China;State Key Laboratory for Geomechanics&Deep UndergroundEngineering,China University of Mining and Technology,Xuzhou 221008,China)

机构地区：[1]中国矿业大学力学与土木工程学院,江苏徐州221116 [2]中国矿业大学深部岩土力学与地下工程国家重点实验室,江苏徐州221116

出　　处：《湖南科技大学学报（自然科学版）》2020年第1期49-55,共7页Journal of Hunan University of Science And Technology：Natural Science Edition

基　　金：国家自然科学基金面上资助项目(51174196)。

摘　　要：为在有下卧隧道的基坑开挖过程中实现及时有效的控制隧道隆起,本文提出局部临时堆载措施,并根据Mindlin公式采用MATLAB软件分析局部堆载的3项参数即堆载力、堆载面积和堆载位置对附加应力的影响,基于某基坑案例采用FLAC3D软件进行正交模拟验证.结果表明,堆载力对隧道隆起影响最大,堆载面积次之,堆载位置最小.隧道隆起值随堆载力增大呈比例减小,并随堆载面积增加而逐渐减小,减小幅度逐渐减缓,且随堆载中心与隧道轴线距离缩短,其影响程度逐渐增大.在实际工程中,优先考虑预留合适尺寸的土体并施加堆载作为局部堆载措施.当隧道位于基坑下部时,局部堆载力不得少于原有土体自重的50%,堆载面积应大于基坑总面积的5%;当隧道位于基坑侧面时,局部堆载力不得少于原有土体自重的1倍,堆载面积应大于基坑总面积的7.5%,才能有效控制隧道沉降.For foundation pit excavation with underlying tunnel,the method of local heap load to control tunnel uplift in timely and effective was proposed.According to the Mindlin formula,MATLAB software was used to analyze the effect of three parameters which is load force,load area and load position on additional stress.Based on the actual case,the FLAC3D software was used for the orthogonal test.The results show that the stacking force has the greatest impact on the tunnel uplift,the second is the load area and the load position is the smallest.The tunnel uplift value decreases proportionally with the increase of the load force.With the increase of the stacking area,the tunnel uplift gradually decreases,however,the decreasing amplitude is gradually reduced,and the distance between the loading center and the tunnel axis is shortened,and the degree of influence is gradually increased.In the project,it is suggested to reserve suitable soil for local loading.For the underlying tunnel,the local load force shall not be less than 50%of the original soil weight,and the piled area shall be greater than 5%of the total pit area.When the tunnel is located on the side of the foundation pit,the local load force shall not be less than 100%of the original soil weight,and the piled area shall be greater than 7.5%of the total pit area.

关 键 词：下卧隧道 隧道隆起 局部堆载 堆载力 堆载面积 堆载位置 

分 类 号：TU921[建筑科学—建筑设计及理论]