摘要
以广东省内花岗岩地区的某隧道工程为例,通过地质测量、遥感分析、岩(土)测试、水文分析和综合测井等手段开展了系统研究,研究结果表明:隧道工程穿越的花岗岩属于典型的硬质岩,其微风化样品的饱和单轴抗压强度约为90 MPa。区域内断裂极为发育,地表水源丰富。微风化花岗岩围岩综合渗透系数0. 008 m/d,断层破碎带围岩和破碎花岗岩围岩的综合渗透系数均为0. 03 m/d,按稳定流理论公式估算隧道涌水量为45 556. 0 m^3/d。隧址区地下水对砼结构腐蚀作用等级为微腐蚀,对砼结构中的钢筋腐蚀作用等级为微腐蚀,化学腐蚀环境作用等级B级。综合测井结果显示,围岩中存在多个断裂破碎带,岩石的放射性总体较弱。隧道的岩温最高为埋深12 m处的33. 2℃,岩温随埋深增加而快速递减至230 m附近的20℃,水位以下的岩温逐渐上升并最终在隧道洞身附近增加至26. 51℃(703附近)。隧道最大主应力σ_(hmax)=23. 2 MPa位于隧道洞身位置(埋深703 m附近)处,计算得出Rc/σ_(max)介于4~7范围并对应了中等强度岩爆。本研究系统的综合勘察结果表明,该隧道工程可能存在偏压段大变形、硬岩岩爆、高压突(涌)水、风化残积层软化及崩塌和岩石破碎带小型塌方或掉块等灾害,同时研究中也提出了相应的防治应对措施。
In this study,a tunnel in the granite area of Guangdong province is taken as an example to learn the key technology of engineering investigation on tunnel of large length,width and depth.During the studying process,the geological survey,RS analysis,geotechnical test,hydrological analysis and comprehensive logging are conducted to learn the engineering geological condition.As shown in the results,the granite cut through by the tunnel belong to typical hard rock,of which saturated uniaxial compression strength is about 90 MPa for the wall rocks with weak-weathering condition.In the area of construction of the tunnel,there are widely distributed fractures and surface water.Due to the results of experiments,comprehensive permeability coefficient of weak-weathering granite wall-stone is 0.008 m/d,fracture zone of fault is 0.03 m/d,while granite fracture zone is 0.03 m/d.According to steady flow theory,tunnel water influx is approximately 45 556.0 m 3/d.The grade for the corrosion of concrete structure and reinforcement inside by the underground water is weak.The level of chemical corrosion for the underground water is B.The comprehensive logging results indicate that there are several fractures in wall stone,while the radioactivity for wall rocks of the tunnel is weak.The highest temperature of the tunnel rock is 33.2℃,which is located with burial depth of 12 m.The temperature decreases rapidly to 20℃at the burial depth of 230 m.Rock temperature below water level shows rising tendency with maximal temperature of 26.51℃in bottom side of the drill hole,which is located at the scope of tunnel.Major principal stress in tunnel equals 23.2 MPa,which located in tunnel trunk with burial depth of 703.8 m.Rc/σhmax is calculated between 4 and 7,which indicated the grade of rock burst is medium.According to the above characteristics,there possibly exist many types of geological hazard,which are large deformation at Biased-pressure Section,rock burst,water inrush with high pressure,Softening and collapse of weathered residual,and small landslide or rock fall from the zone of fracture landslide.Additionally,some relative countermeasures and some advice are also presented.
作者
李红中
张修杰
马占武
刘祥兴
LI Hongzhong;ZHANG Xiujie;MA Zhanwu;LIU Xiangxing(Guangdong Province Communications Planning&Design Institute Co.,Ltd.,Guangzhou,Guangdong 510507,China;Guangdong Provincial Engineering Technology Research and Development Center of Investigation,Design&Consulting of Highway,Guangzhou,Guangdong 510507,China;Research Center for Earth Environment&Resources of Sun Yat-sen University,Guangzhou,Guangdong 510275,China;College of Civil Engineering,Beifang Minzu University,Yinchuan,Ningxia 750021,China)
出处
《公路工程》
北大核心
2018年第5期110-119,共10页
Highway Engineering
基金
广东省交通运输厅科技项目(科技-2016-02-042
2012-02-027)
北方民族大学重点项目(2015KJ13)
北方民族大学校级项目(21400127121500827)资助
关键词
花岗岩
深埋长大隧道
工程地质
广东省
地质灾害
granite
tunnel of large length,width and depth
engineering geological
guangdong province
geological hazard.