地下隧道

The results show that the infinite method is valid in solving problems in infinite domain and thus high precision can be obtained by eliminating the border effect in finite element analysis.

采用具有精确解的无限厚壁圆筒作有限单元法分析和无限单元法分析，通过对这两种分析方法的分析结果的比较得知：无限单元法是解决无限域问题的一种有效的方法，采用这种分析方法进行隧道及地下工程结构分析，可以消除有限单元法所带来的边界效应，从而使计算精度大为提高。

As a result, it is an urgent realistic problem that land subsidence induced by tunneling is forecasted and controlled so as to ensure the safety of close-by building and buried pipeline.

因此，如何在隧道施工过程中防止坍塌并可靠地预计和有效地控制施工所引起的地面沉陷以保护工程沿线建筑物和地下管线的安全，已成为城市地铁工程建设中必须解决的一项重要课题。

Furthermore, bad economic loss and social effect can be brought about. As a result, it is an urgent realistic problem that land subsidence induced by tunneling is forecasted and controlled so as to ensure the safety of close-by building and buried pipeline.

因此，如何在隧道施工过程中防止坍塌并可靠地预计和有效地控制施工所引起的地面沉陷以保护工程沿线建筑物和地下管线的安全，已成为城市地铁工程建设中必须解决的一项重要课题。

And the excavation of tunnels and underground engineering which continuously changes in time and space is a dynamic process. Therefore, research on the structural stability of country rock and support is meaningful and of practical significance to highway tunnel excavation.

隧道和地下工程的开挖是一个在时间和空间上不断变化的动态过程，因此对围岩与支护结构稳定性问题的研究具有一定的理论及实际意义。

But the strata with high ground water level are composed of alluvium clays、 silty clay、 gravels and crushed stone soils in Chengdu;And the shield will drive in the interzone with complicated geologic environment, especially in the strata contained more than 50 percent of grav

而成都地铁工程将主要穿越由冲积粘性土、粉土、砂砾和碎石类土组成的覆盖层，地下水位高，盾构将通过大量地质条件和环境条件均极为复杂的区间，特别是地层中还夹杂有大漂石、胶结砾石层、粉细砂透镜体，隧道围岩中直径大于5cm的砾石含量一般都在50%以上，最大的漂石直径达1m左右，且地面多为建筑物密集的繁华地区，施工难度大，国内尚无先例，在国外也无完全成熟的经验。

By a series of processing and analyzing the three-dimensional space various graphs and images of seismic wave, many mechanical parameters of rock and soil are computed.

通过对三维数据结构的一系列处理分析形成三维空间地震波的各种图形图像，最终计算岩土体多种力学参数，从而实现对隧道及地下工程前方地质情况的判译、预报。

Underground engineering ; Subway ; Subaqueous tunnel ; Paleochannel ; Groundwater environment.

地下工程；地铁；水底交通隧道；古河道；地下水环境

This project is to be considered as a triumph of the art of tunneling over the underground.

这个项目被认为是隧道工程的艺术战胜地下的凯旋。

Research Center of Tunneling and Underground Engineering, Beijing Jiaotong University, Beijing 100044, China

北京交通大学隧道与地下工程试验研究中心，北京100044

Now right to the left of where he is standing is a little tunnel leading underground.

在他所站的位置左边是一个通向地下的隧道。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。