【作者】 韩涛；

【导师】 杨维好； 黄家会；

【作者基本信息】 中国矿业大学 ， 岩土工程， 2011， 博士

【摘要】 根据孔隙含水岩层中冻结法凿井特点和条件,通过理论分析、数值计算、物理模型试验、现场实测相结合的方法,研究了含水基岩单层冻结井壁的受力规律,提出了含水冻结基岩单层井壁的设计理论,并给出了计算公式。首先,根据冻结壁解冻及生产期基岩单层井壁的受力特点,建立了较符合实际的基岩单层冻结井壁力学模型,开展解析分析研究,获得了井壁和围岩体严格的应力与位移解析解;获得了基岩单层冻结井壁受径向外载、井壁与围岩间径向相互作用力的解析解;掌握了井壁与围岩相互作用规律。其次,按照井壁的施工过程,建立了较符合实际的基岩单层冻结井壁受力数值计算模型,获得了井壁所受径向外载,以及井壁与围岩径向相互作用力的数值解。对比分析研究表明:理论解析解与数值解符合很好,表明解析解是正确的,可用之进行井壁设计计算。在含水围岩条件下,围岩体弹性模量、围岩体孔隙率和泊松比的取值对井壁受力和井壁与围岩体接触面特性有较大影响。因此,含水孔隙围岩体冻结前、后的物理力学参数的取值是一个需要高度重视的问题。第三,开展了井壁与孔隙岩体相互作用的模型试验研究。首先,借助正交试验,配制出了由中粗砂、透水混凝土增强剂、水泥和水组成的满足5个相似系数近似等于1的一种多孔隙岩体相似材料。运用环氧型植筋胶配制出了模型井壁材料。然后,运用模拟岩体材料和模型井壁材料制作模型试件,成功进行了富水条件下多孔隙岩体与井壁结构受孔隙水压作用的大型模型试验,获得了孔隙水作用下井壁的受力规律。试验研究表明:在井壁与围岩体界面有一定压应力的条件下,孔隙水压加载过程,井壁受力可明显分为2个阶段。第一阶段,在孔隙水压增大到一定值前,井壁内缘应变基本保持不变或略微增大;超出此定值时,井壁内缘应变与孔压线性变化。第四,针对基岩单层冻结井壁,在内蒙古鄂尔多斯地区马泰壕煤矿风井开展井壁受力的现场实测,获得了井壁在施工期、解冻期、运行期井壁混凝土应变、钢筋受力、井壁外载的变化规律。实测研究表明:实测的井壁未发生与围岩剥离现象,井壁受力较小,井壁是安全的。在冻结壁解冻前后井壁受力的变化规律与理论分析结果相符。最后,综合上述研究成果,提出了富水基岩单层冻结井壁的设计理论与计算方法,并在实际工程的井壁结构设计中得到成功应用。论文有图93幅,表47个,参考文献173篇。更多还原

【Abstract】 Based on the characteristic and conditions of sinking shaft by freezing method in pore water-bearing rock strata, the research on the stress regulation of monolayer freezing shaft lining in water-bearing bedrock was carried out through theoretical analysis, numerical analysis, physical simulation experiment and field measurement. The design theory and calculation methods were put forward for the monolayer freezing shaft lining in water-rich bedrock, as well as the calculation formula.Firstly, according to the stress characteristics of the monolayer shaft lining in the bedrock during the frozen wall thawing period and production period, a relatively practical mechanical model of monolayer freezing shaft lining in the bedrock was established to conduct the analytical analysis research. And consequently, some research results were obtained including the strict stress analytical solutions of shaft lining and surrounding rock, the analytical solutions of the shaft lining with radial load and interaction force between shaft lining and the surrounding rock applied and the change rules of interaction force.Secondly, on the basis of the construction process of the shaft lining, a relatively practical numerical model was established to analyze the stress regulation of the monolayer freezing shaft lining in the bedrock. In addition, the numerical solutions of the shaft lining were also obtained with radial load and interaction force applied. Contrast analysis shows that analytical solutions are consistent with numerical solutions, indicating that the analytical solutions are correct, which can be used to design the shaft lining. Under the conditions of water-bearing surrounding rock, its elastic modulus, porosity and Poisson’s ratio greatly influence the shaft lining stress and the characteristics of contact surfaces between shaft lining and surrounding rock. Therefore, for the pore water-bearing surrounding rock, the different values of physical and mechanical parameters in ex- frozen and post-frozen period need to be paid great attention.Thirdly, the physical simulation study was carried out on the interaction between the shaft lining and pore rock. First, a kind of similar material of porous rock was prepared with the orthogonal test method, which was made of coarse sand, permeable concrete strength additive, cement and water. And its five similarity coefficient is approximately equal to 1. At the same time, the similar material of shaft lining was prepared using epoxy anchorage adhesive. Then, using the simulation model made by with the similar materials, a large-scale simulation experiment was conducted on the characteristics of porous rock and shaft lining with water pressure loaded under water-bearing conditions. And the stress regulation of the shaft lining was obtained with the pore water pressure applied. The experimental studies have shown: when certain compressive stress exist in the interfaces between the shaft lining and the surrounding rock, the stress regulation of the shaft lining can be divided into two stages during the pore water pressure loading. In the first stage, the shaft lining strain in the inner edge remains unchanged or slightly increases before the pore water pressure increases to a certain value; when exceeding this value, the shaft lining strain in the inner edge changes linearly with the pore pressure.Fourthly, aiming at the monolayer freezing shat lining in the bedrock, the field measurement was conducted to monitor the stress on the air shaft in Ma Tai-Hao coal mine, Ordos, Inner Mongolia. The change rules of the concrete strain, reinforcement stress and the load was monitored during construction, thawing and operation period. The measurement studies have shown: the monitored shaft lining didn’t separate from the surrounding rock, which was secure with small stress. The stress regulation of the shaft lining in ex-thaw and post-thaw period was consistent with the theoretical analysis.In the end, based on the above research results, the design theory and calculation methods were put forward for the monolayer freezing shaft lining in water-rich bedrock. The theory of the monolayer freezing shat lining in the bedrock been successfully applied in practical engineering.The paper have figure of 93, table 47, 173 references.更多还原