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岩石洞室地基稳定性研究

Stability Study of Rock Foundation with Caverns

【作者】 王桂林

【导师】 张永兴;

【作者基本信息】 重庆大学 , 岩土工程, 2004, 博士

【摘要】 随着地面与地下空间的综合开发利用日愈增多,地面建筑与地下工程的冲突也日愈突出,地处山区的山城重庆,这类问题尤为突出,研究岩石洞室地基的稳定性已成为重庆市建设中急需解决的一项重要课题。论文结合重庆市轻轨岩石洞室地基工程,全面系统地分析了岩石洞室地基的稳定性问题。论文的主要工作和结论有: (1) 全面分析了岩石洞室地基的破坏模式及稳定判据,提出了岩石洞室地基的破坏存在下列三种典型破坏模式:①仅建筑地基破坏,洞室无破坏;②地下洞室破坏,地基无破坏;③建筑地基和地下洞室同时破坏。岩石洞室地基稳定性涉及地面建筑与地下洞室两者的安全与稳定,因此稳定判据应以地面建筑地基与地下洞室两者的强度、变形双控制,任一项超过安全控制标准则视为破坏。 (2) 根据建筑地基附加应力的影响深度及地基洞室次生应力的影响范围,将岩石洞室地基分为深埋洞室地基、浅埋洞室地基和洞室无影响地基三大类。对浅埋圆形洞室地基可根据弹性力学的复变函数法,得到浅埋圆洞地基平面应力位移的解析解;对于深埋圆形洞室地基可视为一个双向受压无限板孔应力集中问题,由此也得到其弹性理论解析解。 (3) 运用有限元数值分析技术,采用强度折减法、加载系数法对多个洞室地基模型进行了模拟对比分析,结果表明开洞地基处于加载状态,适宜采用加载系数法来分析其稳定性,而地基开洞可用有限元法强度折减来研究其稳定性。 (4) 提出了用塑性区面积相对比等强度、变形安全指标来综合确定岩石洞室地基安全系数的方法,通过实例分析表明,此方法是可行的。 (5) 由于稳定性数值分析比较费时,论文将均匀试验设计方法与自适应神经模糊系统(ANFIS)相结合,用均匀试验设计选取特征样本点,利用ANFIS进行近似稳定性数值分析,据此建立了洞室地基稳定性智能识别系统。实例应用分析表明,利用该系统稳定性评价简便快速且结果可信。 (6) 通过对重庆市地基开洞和开洞地基两例复杂的洞室地基工程实例分析及其他工程的研究总结,提出了研究复杂洞室地基稳定性的综合分析方法推荐思路框架。 在上述研究中,通过将判据研究、数值分析、智能识别、传统计算成果与工程监测结论相对比,结果表明,研究成果与工程监测结论基本吻合,说明文中的重庆大学博士学位论文研究成果是合理可信的,对岩石洞室地基实际工程的决策、设计和施工具有重要的意义。

【Abstract】 With the increase of urban underground and ground engineering, the conflict between ground building and underground engineering is more and more. It is more important to evaluate accurately the stability of rock foundation with caverns. It becomes a special outstanding and urgent problem to study stability of rock foundation with caverns in Chongqing mountain city. In the dissertation, systematic research of rock foundation with caverns is carried out by combining with Chongqing light rail rock cavern foundation. Main conclusions are summarized as follows:(1) Failure model and stability criterion of rock foundation with caverns is carefully researched in this dissertation. The author classifies the cavern foundation into three typical failure model as follows: 〨round building is failure but cavern is safe; ヽavern is failure but ground building is safe; 〣oth ground building and cavern are failure. For ground building’s safety and cavern’s safety, stability criterion of rock foundation with cavern is controlled by safety strength and deformation of ground and underground engineering.(2) According to influencing depth of foundation ground additional stress and influencing scope of deuterogenous stress of cave under foundation, the author classifies the cavern foundation into three types, that is, deep burying cavern foundation, shallow burying cavern foundation and cavern foundation without influence of cavern. Analytical solution of stress and displacement from shallow burying cavern foundation can be determined by using the theory of elastic mechanics. For deep burying cavern foundation, it is treated as a problem of infinite plate containing a hole, whose analytical solution can be obtained by using elasticity theory.(3) By using strength reduction FEM and load-increasing FEM, the author proposed that the foundation with an opened cavern is subjected to loading. As a result, load-increasing FEM is suitable for stability analysis of foundation with an opened cavern, but for foundation with an opening cavern, strength reduction FEM is feasible.(4) The ratio of between plastic zone area and cavern area, etc, is proposed to determine the safety factor of cavern foundation. The results from the realistic example show that the method is feasible.(5) By combining adaptive-network-based fuzzy inference (ANFIS), which provides an analytical approximation of the true FEM calculation, and uniformexperimental design, which select typical sample points, intelligent identification system to analyse the stability of cavern foundation is established. The results from the realistic example show that the present intelligent identification system is efficient.(6) Based on the analysis of two complex rock cavern foundation engineering examples in Chongqing city, this dissertation provides a synthesized analysis method, and recommend the research route for study stability of complex cavern foundation.Results obtained in the dissertation are basically consistent with the results by in-situ monitoring. It is showed that the method and theory in the dissertation are reasonable, and important for decision, design and construction of rock foundation with a cavern.

  • 【网络出版投稿人】 重庆大学
  • 【网络出版年期】2005年 01期
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