| 卸荷条件下三峡地下厂房大型联合块体稳定性的三维数值模拟分析 |
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| 引用本文： | 黄润秋,黄达,宋肖冰.卸荷条件下三峡地下厂房大型联合块体稳定性的三维数值模拟分析[J].地学前缘,2007,14(2):268-275. |
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| 作者姓名： | 黄润秋 黄达 宋肖冰 |
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| 作者单位： | 成都理工大学,地质灾害防治与环境保护国家专业实验室,四川,成都,610059;成都理工大学,地质灾害防治与环境保护国家专业实验室,四川,成都,610059;长江水利委员会,三峡勘测研究院,湖北,宜昌,443003 |
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| 摘 要： | 块体稳定性分析一般采用只考虑重力条件下的刚体极限平衡方法来进行计算,而没有考虑开挖卸荷后块体的二次应力场对块体的稳定性的影响。文中按照实际施工工序,对三峡地下电站主厂房的两大型顶拱边墙联合块体进行三维数值模拟分析。分析结果表明:块体的顶拱部分在开挖过程中垂直厂房轴线的水平方向始终为受压状态且压应力随开挖过程逐渐增大(其很难沿结构面“爬坡”失稳,因此对结构面的起伏度进行了研究,并统计确定了其在结构面强度参数中的贡献),而垂直应力在顶拱开挖结束时卸荷基本结束,变形相对较小,沿滑面向开挖区滑移;块体的边墙部分在两个方向均表现为卸荷,特别是垂直厂房轴线的水平方向卸荷明显,在其表部甚至出现拉应力区,变形以向开挖区水平变形为主,水平方向变形量为竖向变形量的7～9倍,且总变形量较顶拱部分大得多,因此块体边墙部分在失稳前并非沿块体滑面滑移,而是向开挖区水平卸荷回弹为主。基于数值模拟结果,对块体的可能失稳的变形规律和应力分布特征进行了分析,并且提出了块体稳定度的概念,从而对其稳定性作出相应的评价。
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| 关 键 词： | 三峡 地下厂房 块体 卸荷 应力 变形 稳定性 数值模拟 |
| 文章编号： | 1005-2321(2007)02-0268-08 |
| 修稿时间： | 2006年6月2日 |
3-D numerical simulation of stability of large associated blocks for an underground powerhouse in the Three Gorges, Yangtze River, under the condition of unloading |
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| Huang Runqiu,Huang Da,Song Xiaobing.3-D numerical simulation of stability of large associated blocks for an underground powerhouse in the Three Gorges, Yangtze River, under the condition of unloading[J].Earth Science Frontiers,2007,14(2):268-275. |
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| Authors: | Huang Runqiu Huang Da Song Xiaobing |
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| Abstract: | The stability of a block is commonly analyzed based on rigid body limit equilibrium theory only by considering gravity, while the secondary stress field after excavation of the block is usually not taken into account. This paper makes 3-D numerical simulation of two large associated blocks in the Three Gorge project along the Yangtze river for an underground powerhouse . The results show that parts of the blocks' crown zone are under compressive stress, which gradually increases as the underground powerhouse is excavated in a horizontal direction, perpendicular to the powerhouse' axis.The vertical stress almost entirely unloads when the crown is completely excavated, with the crown zone comparatively sliding less along potential sliding face towards the excavation zone. The stress of the wall side zone is unloaded in two directions, especially in the horizontal direction perpendicular to the powerhouse' axis. There are some tensile stress zones in their surface, the deformation of the wall side zone is mainly a horizontal displacement towards the excavation zone The tilt of the horizontal displacement is 7 to 9 times that of vertical displacement. The total displacement of the wall side zone is much larger than that of the crown zone, so, the wall side zone does not slide along potential sliding face before failure Based on this numerical simulation, thes analyze the deformation and stress characteristics of the blocks put forward concept of stability degree of the blocks and evaluate their stability. |
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| Keywords: | Three Gorges underground powerhouse block unloading stress deformation stability numerical simulation |
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