【作者】 王遇国；

【导师】 梅志荣；

【作者基本信息】 中国铁道科学研究院 ， 桥梁与隧道工程， 2010， 博士

【摘要】 我国岩溶地区幅员辽阔,地下水环境复杂,随着铁路隧道建设向长、大、深方向发展,在这些地区修建铁路隧道,岩溶构造突水是人为激发的最严重的施工地质灾害。岩溶地区修建长大隧道,往往遭遇到富水、高水压、暗河、溶洞及断层等问题,开挖施工极易诱发大规模的突水、突泥等灾害;同时,突水、突泥会严重破坏地下水环境,改变地下水渗流场及补排关系,造成地下水资源减少和枯竭,导致水质污染和破坏。本文结合岩溶地区隧道工程建设实例,分析总结了岩溶隧道突水灾害发生规律与特征;运用断裂力学和突变理论分析了岩溶隧道突水发生机理和过程,在岩溶构造与隧道间最不利平面关系分析基础上,提出了防突岩层概念,并从断裂破坏和失稳破坏的角度阐述了岩溶构造防突岩层安全厚度问题,推导出有关结论;针对岩溶隧道突水注浆防治关键技术,进行了注浆材料室内模拟实验;基于浆液粘度时变特性,研究分析了浆液在砂层及裂隙中的扩散机理,可根据浆液扩散机理进行控制注浆;同时,对岩溶隧道突水灾害的“避、绕、堵、排和固”的防治措施进行了案例分析。本文的研究结果主要包括以下几个方面:(1)以岩溶隧道为研究对象,结合施工现场发生的突水突泥情况,分析总结了突水突泥的基本规律、灾害特征、防治方法及处理措施。(2)通过对多个工程工况分析,应用断裂力学原理,研究了岩溶构造防突岩层处于压剪、拉剪应力状态下,其裂隙方向、裂隙长度、围压及水压力对岩体强度的影响;将岩溶构造防突岩层简化为平面应变固支梁,推导了了简化模型的应力状态公式;岩溶构造防突岩层的裂隙可能处于拉剪、或压剪应力状态,根据裂隙应力状态及裂隙断裂判定方法,可得到防突岩层裂隙断裂的临界厚度。(3)提出了“防突岩层”的概念,并分析了岩溶构造防突岩层失稳突水机理,及参数变化对岩溶构造防突岩层失稳突水的影响;分析了水压、岩溶充填体重力及岩溶构造防突岩层重力作用下的岩溶构造防突岩层失稳突水的安全厚度。(4)分析了岩溶隧道突水灾害发生的后果;由于钻孔等地质预报手段存在误差和局部性,将岩溶构造防突岩层分为若干承载梁板力学模型,运用可靠度理论研究了岩溶构造防突岩层破坏的突水风险;通过比较交通、大坝等灾害风险标准,建立了岩溶隧道突水灾害的风险标准;利用VISUAL BASIC 6.0编制了数据管理系统,可以对灾害的数据信息资料进行收集、管理,并对突水灾害风险进行评定。(5)对普通硅酸盐水泥添加纳米灌注剂进行了不同水灰比的浆液流动性试验,并和普通硅酸盐水泥的浆液流动性进行了比较,给出了添加纳米灌注剂的普通硅酸盐水泥水灰比建议值;基于相同流动性,将普通硅酸盐水泥和添加纳米灌注剂的普通硅酸盐水泥的浆液析水收缩性进行了比较研究;添加不同纳米灌注剂掺量进行了试验,给出了普通硅酸盐水泥浆液的纳米灌注剂参量建议。采用充填砂模拟了浆液在砂体中的渗透扩散;分别用铁板、玻璃板模拟裂隙,进行了浆液在裂隙中的注浆效果研究。(6)针对岩溶隧道大裂隙涌水及钻孔涌水的注浆封堵,进行了添加纳米灌注剂的水泥水玻璃双液浆凝胶试验,测试了不同水泥水玻璃体积比的浆液凝胶时间;对水泥水玻璃体积比1:1的浆液,测试了不同波美度的浆液凝胶时间,并分析了该双液浆凝胶时间变化随波美度变化关系。(7)基于浆液粘度时变特性,建立了粘时变体浆液在充填砂体、裂隙中的扩散模型;分析了浆液扩散范围与充填砂体的渗透系数、岩溶构造防突岩层裂隙宽度、注浆压力、注浆钻孔孔径及凝胶时间的关系;依据粘时变流体模型,可以进行岩溶构造防突岩层、溶腔充填体注浆的合理选材、合理注浆压力、钻孔孔径和浆液扩散范围控制,防止跑浆、串浆。(8)根据岩溶隧道突水灾害发生机理及突水风险,对排水降压、注浆封堵相结合的岩溶隧道涌突水灾害防治方法进行了研究,结合工程实例进行了分析。将粘时变浆液扩散理论应用在大支坪隧道“990”溶腔异常体注浆,串浆、跑浆、注浆压力不上升等问题得到了较好的解决。更多还原

【Abstract】 The water inrush scourge was a very serious problem for karst existing in most areas of our country. Longer、bigger and deeper tunnels would be built with the railway running faster and faster. Karst water inrush scourge might come forth when the tunnel was excavated, if the tunnel was built in these areas, where existed plentiful water, high pressure of water, karst cave and faultage, and which could lead to the loss and pollution of groundwater.In this paper, the basic law of tunnel hazard was summarized. The water inrush mechanism of tunnel karst was analyzed by fracture mechanics and catastrophe theory, and the safe thickness of rock wall, which to prevent the water inrush, was educed respectively from fracture failure and instability theory. The grout pervasion mechanism was inferred based on viscosity varying characteristics with time and laboratory simulation test, which could be used to control the grout pervasion areas. The prevention measures, which included“avoiding, bypass, block water up, drainage and reinforce”, was discussed in combination with engineering construction. This paper mainly included the following aspects:(1) The karst water inrush was summarized in combination with the tunnel construction, which included the law, scourge characteristics, prevention methods and treatment measures of karst water inrush.(2) The rock strengthσ1 was affected by some factors that included the fissure direction、fissure length、confine pressureσ3 and fissure water pressure, when it suffered from pressure shear stress states or tensile shear stress states respectively. The rock wall to prevent the water inrush was simplified plane strain fixed end beam, and its stress states was answered by simplified model. The critical states of fissure rupture was analyzed when it suffered from different stress states, which included pressure shear stress or tensile shear stress respectively, and the safe thickness of the rock between karst and tunnel was determined by the fissured fracture critical state of karst water inrush.(3) Based on catastrophe theory, two aspects were analyzed, one was instability mechanism of the rock between karst and tunnel, the other was the parameter variation that influenced on the rock instability, then the safe thickness of the rock could be anwsered. (4) The karst inrush disaster results were analyzed firstly, then the risk of water inrush disasters was studied by reliability theory to meet with the errors and local of drilling hole and other geological prediction methods. By comparing with different risk criteria, which of karst water inrush was established, and data management system was developed by use of VISUAL BASIC 6.0, which could be used to manage the data information, determine the disaster risk.(5) Firstly, mixing nano perfusion agents with portland cement together, and adding different water cement ratio to test its mobility that was compared with portland cement’s mobility, which gave the water cement ratio recommendatory values of mixing nano perfusion agents with portland cement together. Secondly, based on the same grout mobility, grout shrinkage was tested and compared between mixing nano perfusion agents with portland cement together and portland cement, and gave the recommendatory values, which blended nano perfusion agents with portland cement. Sand was used to simulate the seepage of grout filling, and the used to simulate the grouting effect of rock cranny.(6) In order to overcome the inflow of fissure and drilling hole, having carried out a experiment to test the two liquid grout gel time of cement and water glass that added nano perfusion agent, and test the gel time of different cement ratio and water glass, and test the gel time of different baume degrees when the ratio of cement and water glass was 1:1, and analyzed the change law of gel time.(7) Based on the viscosity varying characteristics with time, a pervasion model of sand or fissure grouting was established, and some affection factors to pervasion areas, which included pervasion coefficient of different sand, fissure length, grouting pressure, grouting drill hole diameter, gel time, were analyzed. The reasonable grouting parameter, which included material, grouting pressure, drilling hole diameter and pervasion areas, could be adopted to prevent the grout diffusing to more areas when grouting in the rock between tunnel karst cave.(8) According to the mechanism of karst water inrush, the application technology about water buck and grouting of karst water inrush scourge with engineering congstruction.更多还原