支护结构

The isograph of soil displacement, the distribution map of active pressures, the crack depth between the wall and soil, and the settlement influence areas radius of the cantilever sheet pile wall have been gained successfully.

并求证了拉锚式支护结构的锚固力F对控制支护土体变形的有利影响。

Further more, design scheme and main technical measures of dewatering and compound support are introduced in detail.

详细介绍了基坑降水及组合支护设计方案、主要技术措施，并对支护结构及周边建筑沉降和位移及基坑内地下水位进行观测。

Considering the theory of roadway support in soft rock, we proposed an active support mode based on study of rheology of weak adjacent rock, complex stress environment, and destabilization of original supports. Fully grouted bolt, extension grouted cable that can strengthen self-bearing capacity and entirety are used. Original support scheme and reinforcement scheme are simulated by means of FLAC(superscript 3D).

在分析硐室围岩岩性、软弱围岩流变、复杂应力环境及原支护结构失稳的基础上，结合软岩巷道围岩控制理论，提出了以全长锚固锚杆、锚索增强围岩整体性和自承载能力的主动支护，并以底板锚注加底拱返修加固。

The presentation introduces conditions, features and difficulties in the recovery project of Shanghai Metro Line 4, by stating cons and pros of overall proposal of recovery design, the safeness of support and bracing structure for hyper deep foundation, influence of mid-river cofferdam on existing sound tunnel and hyper deep foundation, structural design selection for connection section of the mined tunnel, water-proofing option for hyper deep foundation in confined aquifer soil.

报告介绍了上海地铁4号线修复工程建设条件、特点和难点，陈述了对修复设计总体方案取舍、超深基坑支护结构安全度、江中围堰对完好隧道及超深基坑的影响、暗挖连接段的结构设计方案选择、处于承压含水层中的超深基坑的结构防水等内容。

Outline of the Presentation The presentation introduces conditions, features and difficulties in the recovery project of Shanghai Metro Line 4, by stating cons and pros of overall proposal of recovery design, the safeness of support and bracing structure for hyper deep foundation, influence of mid-river cofferdam on existing sound tunnel and hyper deep foundation, structural design selection for connection section of the mined tunnel, water-proofing option for hyper deep foundation in confined aquifer soil.

报告内容介绍报告介绍了上海地铁4号线修复工程建设条件、特点和难点，陈述了对修复设计总体方案取舍、超深基坑支护结构安全度、江中围堰对完好隧道及超深基坑的影响、暗挖连接段的结构设计方案选择、处于承压含水层中的超深基坑的结构防水等内容。

The strengthened depth and so on; on the other hand, the compound mode of those influencing factors in the design and the difference of theoretical model should not be ignored, So, a state equation of limit equilibrium, which was applied to stability analysis of soil nail structure, was set up considering the influence of inter-slice force and combining the idea of disturbance force of Sarma with slice method. In the design of timbering of excavation, the reliability theory was used to analyze not only the sensitivity of random variables, including index of reliability and safety factor, but also the relationship between them.

因此，在理论分析模型方面，应用Sarma所提出的扰动力概念与条分法相结合，建立了考虑条间作用力影响的土钉支护结构稳定分析极限状态方程；在开挖支护设计方面，运用可靠度理论分析了各项设计参数及其组合方式对安全系数与可靠度影响的敏感性，以及安全系数与可靠度的相互关系。

Structurally speaking, the pit tunnel project is the use of works covered by the upper layer and the engineering supporting structure together constitute the load-bearing structure works.

从结构上讲，坑地道工程是利用工程上部覆盖层与工程支护结构共同组成的承载结构的工程。

The fore bay of Heihe Longhui Hydropower Station designed by the company, is the existing biggest tunnel fore bay in China, which is height of 21m, width of 16m; for the large-span dome of surge tank of Baishuijiang Shiji Hydropower Station, which is the first project equipped with rapid-drop gate in surge tank in Gansu Province, the company adopted pre-stressed anchor cable to complete the dome's excavation and supporting at the same time, thus reduced the completion period and investment; for the diversion tunnel of Fuchuan Hydropower Station, which is the biggest non-pressure diversion tunnel in Gansu Province, with span of 9m, height of 11m, the company adopted half-tunnel supporting structure, thus reduced the project investment.

黑河龙汇水电站前池是目前国内最大的洞内式前池，跨度16m、高度21m；白水江石鸡水电站调压井大跨度穹顶采用预应力锚索技术，分瓣开挖一次支护完成，节省了工期和造价，同时是省内第一座在调压井内设置快速闸门的工程；福川水电站引水隧洞是甘肃省内最大的无压引水隧洞，跨度9.0m，高度11m，采用半洞支护结构，在满足安全的前提下节省了工程投资。

The problems about safety and durability of bolt and cable-supported structures are presented.

1引言 锚固类结构主要指锚索、锚杆和土钉一类岩土工程常用加固、支护结构，在非临时性工程中，还包含加筋土结构。

The factor of safety increases greatly with the increase of the length of nail.

土钉支护大大增加了墙后土体的自稳能力，改变土钉的长度，能显著改变支护结构的安全系数。

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。