QUANTITATIVE EVALUATION OF THE BEARING CAPACITY OF SURROUNDING ROCK MASS AND THEORETICAL CONSTRUCTION OF THE CHARAVTERISTIC CURVE OF TUNNEL SUPPORT FOR NATM

新奥法围岩承载力定量评价及隧道支护特征曲线理论构建

基本信息

批准号：
13650542
负责人：
KIYAMA Hideo
金额：
$ 2.3万
依托单位：
TOTTORI UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2002
项目状态：
已结题

项目摘要

Active mobilization of bearing capacity of rock mass surrounding an underground opening characterizes the NATM (New Austrian Tunneling Method) concept of supporting. There have been many attempts to give quantitative expressions for this capacity but no one has ever completely solved the question. In the first part of this paper theoretical relations between support pressure and tunnel wall displacements are briefly discussed. We derive a simplified solution of a circular lined-tunnel in an elastic ground under the plain strain for full-slip and no-slip conditions. These two conditions at the ground-lining interface make it possible to explain the effects of shear stress transmission and relative shear displacement. The lateral free-field ground stresses for this solution are restricted to a fixed value of the vertical stresses (σ_v* = -p, σ_H* = -kp). An actual tunnel opening is excavated and supported after the load corresponding to the free-field stresses. We introduce an assumption … More of the actual "excavation unloading" conditions that occur during tunneling. By advancing this derivation, the strict solution is utilized successfully to construct a theoretical characteristic curve of tunneling. The characteristic curve shows clearly the bearing capacities of a tunnel lining, the surrounding ground and the total by using an index "relative-support-stiffness".The elastic theory of the stress distribution around tunnels demonstrates that the deviatoric stresses are maximum at the periphery of the excavation. Discussion here should include the dependence of the characteristic curve on the zone of yielded ground and the discontinuity in the ground. We have carried out numerical simulations for a discontinuous ground with Distinct Element Modeling. The realistic ground reaction curves by the analyses are examined with the theoretical solution derived above. We will learn that while the ground may work, more or less, as a load bearing structural component to the load corresponding to the free-field stresses, overestimation must be avoided. Less

围绕基础开口的岩石质量的轴承能力的主动动员表征了NATM（新的奥地利隧道方法）支持的概念。已经有很多尝试为这种能力提供定量表达方式，但是没有人完全解决了这个问题。在本文的第一部分中，简要讨论了支撑压力和隧道壁位移之间的理论关系。我们在弹性地面中的弹性地面中的圆形衬里隧道的简化溶液在全滑且无滑动条件下得出。地面界面处的这两个条件使解释剪切应力传递和相对剪切位移的影响是可能的。该解决方案的侧向自由场应力仅限于垂直应力的固定值（σ_v* = -p，σ_h* = -kp）。载荷对应于自由场应力后，挖掘并支撑了实际的隧道开口。我们引入了一个假设……更多实际的“开挖卸载”条件。通过推进这种推导，严格的解决方案被成功地用于构建隧道的理论特征曲线。特征曲线清楚地表明了隧道衬里的轴承能力，周围的地面和总体使用索引“相对支撑状态”。隧道周围应力分布的弹性理论表明，偏离应力是在开发的外围时最大的。这里的讨论应包括特征曲线对屈从地面和地面不连续性的依赖性。我们已经为具有不同元素建模的不连续的地面进行了数值模拟。通过上面得出的理论解决方案检查了分析的现实地面反应曲线。我们将了解到，尽管地面可能会或多或少地起作用，因为必须避免避免高估的负载与自由场应力相对应的负载。较少的