【作者】 张颖；

【导师】 许模；

【作者基本信息】 成都理工大学 ， 环境地质， 2009， 硕士

【摘要】 四川盆地及盆地边缘地区红层分布极为广泛,出露总面积约为16.5万km2,其中四川省境内约为12万km2,占全省总面积的25%左右。红层主要为侏罗纪和白垩纪地层,岩性较软弱,工程地质特性较差。该区内水资源时空分布不均,需要建设水利工程实现调节。已建及在建的多个水利工程存在的工程地质问题日益凸显,坝基岩体渗漏是主要问题之一。探讨四川盆地红层岩体渗透特性,对水利工程建设的可持续发展有着重要意义。基于四川盆地红层岩体的地形地貌、地质构造、沉积背景、地层岩性、水文地质特征,将四川盆地划分为盆西北区、盆中区、盆南区三个工程地质区。以二十一个水利工程勘察数据为依托,系统地读取了300个钻孔的4,300组数据,重点探讨了四个和岩体渗透性具有较强相关性的影响因素:岩性因素、风化因素、构造因素、易溶组分因素对渗透性的控制作用。详细分析了各水利工程和工程地质区内红层岩体的渗透特性。统计分析结果表明,岩体透水性与各因素之间呈现一定的规律性,各工程地质区内地质特征的差异也导致岩体渗透性在空间上分布各不相同。具体成果如下:(1)岩性因素为控制岩体渗透性最重要的因素。在新鲜岩体中,砂岩夹泥岩类透水率为8~12Lu,泥岩夹砂岩类透水率为2~8Lu,互层类透水率为0~5Lu,泥岩类透水率为0~1Lu。(2)在风化影响下,强风化岩体透水率常达到100Lu以上,弱风化岩体透水率为5~100Lu,新鲜岩体透水率多为10Lu以下。(3)三种源于构造作用的软弱夹层在不同岩性组合的钻孔试段中透水率范围不尽相同。在岩性组合为砂岩夹泥岩类的试段中,岩块岩屑型层间错动带透水率在10~53Lu之间,岩屑夹泥型层间错动带透水率在4~22Lu之间,泥夹岩屑型层间错动带透水率均在2~4.25Lu之间。在岩性组合为泥岩夹砂岩类的试段中,岩块岩屑型层间错动带透水率在6~29Lu之间,岩屑夹泥型层间错动带透水率在2.6~15Lu之间,泥夹岩屑型层间错动带透水率均在1~4Lu之间。在岩性组合为互层类的试段中,岩块岩屑型层间错动带透水率在5~22Lu之间,岩屑夹泥型层间错动带透水率在1.5~13Lu之间,泥夹岩屑型层间错动带透水率均在0.9~3.4Lu之间。在岩性组合为泥岩类的试段中,岩块岩屑型层间错动带透水率在2~15Lu之间,岩屑夹泥型层间错动带透水率在1.8~7Lu之间,泥夹岩屑型层间错动带透水率均在0.25~1.4Lu之间。(4)易溶组分溶蚀形成孔洞,造成地下水渗流量增加。易溶组分含量与岩体透水率呈正比。(5)盆西北区渗透特性主控因素为岩性因素和易溶组分因素,盆中区渗透特性主控因素为岩性因素和风化因素,盆南区渗透特性主控因素为岩性因素和构造因素。(6)建立地下水渗流有限元模型对地下水运动情况进行模拟,得出红层地区水利工程坝基岩体渗流问题的产生模式和影响程度,实现岩体渗透特性对水利工程的控制作用。更多还原

【Abstract】 There is widespread red rock in Sichuan Basin and its marginal area. Total about 165 thousands km2 red rock is on the ground. In Sichuan Province, there is about 120 thousands km2 red rock which takes 25% of total Sichuan’s area. Most of the red rock is Jurassic and Cretaceous layer. Its lithology is soft, attribute of geological engineering is weak. Because the water resource is uneven distribution on time and space in this area, there is a demand for building water conservancy engineering to regulate it. The geology problems of the built and building water conservancy engineering have gradually come out, and foundation leakage is one major question. Study on the permeability properties of Sichuan Basin’s red rock is important for sustainable development of water conservancy engineering.Based on the topography, geological structure, sedimentation background, lithology, hydro-geological characteristics of Sichuan Basin Red Rock, divided Sichuan Basin to three zones: the northwest zone, the middle zone and the south zone. Relying on reconnaissance data of twenty-one water conservancy engineering, systematically read 4,300 group of data of 300 drilling holes, discussed mainly the controlling effect of four significantly correlated influencing factors of rock permeability properties: lithological factors, weathering factor, geological factors, easily dissolved component factors on permeability properties. Detailed analyzed the red rock permeability properties of each water conservancy engineering and engineering geological zone.The analysis shows that there’s a certain regulation between rock permeability and the factors, and the rock permeability properties are different because of the difference of geological characteristics between the engineering geological zones. Through the research, following achievements have been made:(1) The lithological factor is the most important controlling factor of rock permeability properties. In fresh rock, the permeable rate of sandstone intercalated with mudrock is 8~12Lu, the permeable rate of mudrock intercalated with sandstone is 2~8Lu, the permeable rate of intercalation is 0~5Lu, the permeable rate of mudrock is 0~1Lu.(2) Influenced by weathering factor, the permeable rate of hard weathered rock is commonly more than 100Lu, the permeable rate of soft weathered rock is 5~100Lu, and the permeable rate of fresh rock is less than 10Lu.(3) Three types of soft intercalations born of tectonism which are on the drilling segment with different lithological combination have different permeable rate range. On the drilling segment with sandstone intercalated with mudrock, the permeable rate of inter-laminar dislocation band of rock cuttings is 10~53Lu, the permeable rate of inter-laminar dislocation band of rock cuttings intercalated with mud is 4~22Lu, the permeable rate of inter-laminar dislocation band of mud intercalated with rock cuttings is 2~4.25Lu. On the drilling segment with mudrock intercalated with sandstone, the permeable rate of inter-laminar dislocation band of rock cuttings is 6~29Lu, the permeable rate of inter-laminar dislocation band of rock cuttings intercalated with mud is 2.6~15Lu, the permeable rate of inter-laminar dislocation band of mud intercalated with rock cuttings is 1~4Lu. On the drilling segment with intercalation, the permeable rate of inter-laminar dislocation band of rock cuttings is 5~22Lu, the permeable rate of inter-laminar dislocation band of rock cuttings intercalated with mud is 1.5~13Lu, the permeable rate of inter-laminar dislocation band of mud intercalated with rock cuttings is 0.9~3.4Lu. On the drilling segment with mudrock, the permeable rate of inter-laminar dislocation band of rock cuttings is 2~15Lu, the permeable rate of inter-laminar dislocation band of rock cuttings intercalated with mud is 1.8~7Lu, the permeable rate of inter-laminar dislocation band of mud intercalated with rock cuttings is 0.25~1.4Lu.(4) The holes dissolved by easily dissolved component increase the discharge of groundwater. The content of easily dissolved component is proportional to rock permeable rate.(5) The lithological and soluble salt factors are main controlling factors in the northwest zone, the lithological and weathering factors are main controlling factors in the middle zone, the lithological and geological factors are main controlling factors in the south zone.(6) Establish finite element model of groundwater seepage to simulate the movement of groundwater. Concluded the pattern and the degree of influence of the possible range of rock permeability. Achieve the control of rock permeability to water conservancy engineering.更多还原