浅埋偏压小净距隧道围岩压力及施工力学研究

【作者】 彭琦；

【导师】 李亮；

【作者基本信息】 中南大学 ， 道路与铁道工程， 2008， 硕士

【摘要】 浅埋偏压小净距隧道是一种介于分离式隧道和连拱隧道之间的隧道结构形式,该结构形式比连拱隧道施工工艺更简单,且易于防水处理和控制造价。本文以工程实例为背景,对偏压小净距隧道围岩压力的理论与数值计算方法进行了研究,并对其采用不同工法的动态施工进行了数值分析。通过理论计算与数值分析,本文主要获得了如下研究成果:1.结合岩土材料的强度特性及本构关系,对新奥法中围岩与支护的共同作用力学原理进行了讨论;2.根据前人的有关围岩压力理论和方法,改进了小净距偏压公路隧道围岩压力的计算方法,推导了相应的围岩压力计算公式;3.结合工程实践,分别采用小净距偏压公路隧道围岩压力计算方法和数值模拟方法,分析了隧道围岩的竖向应力和水平侧压力的分布规律,讨论了在不同斜坡坡度、不同埋深和不同净距条件下围岩压力的分布特征及变化规律;4.将数值模拟与理论分析两种研究结果进行分析比较,分析两者存在的差异,论证了上述工程条件下围岩压力理论计算公式的可靠性,并得出了相关结论;5.对浅埋偏压小净距隧道不同施工方法(台阶法、单侧壁导坑法、双侧壁导坑法)进行数值模拟。更多还原

【Abstract】 Unsymmetrical loading neighborhood tunnel with shallow depth is a tunnel structure which interposes between the separable tunnels and multi-arch tunnels. Such tunnel structures are less complicated than multi-arch tunnel technology, easier to be dealt with water-proof technology and limit the construction expenses as well. Taking the practical engineering as example, this thesis is devoted to theoretical and numerical calculation methods on surrounding rock pressure in the unsymmetrical loading neighborhood tunnels, the numerical simulation in different construction methods are analyzed as well. By completing the theoretical calculation and numerical simulation, following research contribution are achieved:1. The interaction mechanics theory of surrounding rock and supporting tunnel in New Austria Tunneling Method is discussed by combining the intensity characteristics and constitutive relation of geotechnical materials;2. Based on forerunners’ relevant theories and methods on surrounding rock pressure, the calculation methods of surrounding rock pressure of unsymmetrical loading neighborhood tunnel are promoted; with the relevant calculation formulas of surrounding rock pressure deduced as well;3. In accordance with the practical engineering, by adopting the theoretical calculation method and numerical simulation of surrounding rock pressure in unsymmetrical loading neighborhood tunnels, the distribution law of vertical stress and horizontal lateral compression of tunnel surrounding pressure are analyzed, the distribution characteristics and changing law of surrounding rock pressure due to different slope gradient, tunnel depth and tunnel net distance are discussed;4. The results of numerical simulation and theoretical calculation formulas are analyzed and compared, the reliability of theoretical calculation formulas of surrounding rock pressure under the aforementioned conditions are demonstrated, and the conclusion are achieved; 5. The numerical simulation of different construction methods (up and down steps, single sidewall guide pit, dual sidewall guide pit) are applied in the unsymmetrical loading neighborhood tunnel.更多还原