岩溶施工勘察及处理专项施工方案.docx

1、岩溶施工勘察及处理专项施工方案一、工程概况1.1 工程总体概况宜昌市轨道交通5号线第一标段包含了4站5区间，分别为起点至南三环站区间、南三环站、出入场线、南三环站至白沙五路站区间、白沙五路站、白沙五路站至青菱站区间、青菱站、青菱站至江国路站区间、江国路站，线路总长7.7Km，全部为高架车站和高架区间。其中青江区间和江国路站处于岩溶发育地段。1.2 工程地质和水文条件1.2.1工程地质条件1.2.1.1青菱站江国路站区间 岩溶发育区域地质情况拟建工程场地地貌单元上均属河流堆积平原，为长江级阶地，地形平坦，地表高程一般介于20.31m21.85m之间，相对高差1.54m，拟建线路沿现有道路烽胜路由

2、南向北展布，道路两侧多为居住小区，少数为空地。拟建场地上部由人工填土层（Qml）、第四系全新统冲积（Q4al）一般黏性土、互层土及砂性土组成；下伏基岩主要有白垩-下第三系东湖群（K-E）dn泥质粉砂岩、砾岩、三叠系下统大冶组（T1d）灰岩、二叠系上统大隆组（P2d）黏土岩、二叠系下统栖霞组（P1q）灰岩、石炭系上统黄龙组及船山组（C2h+c）灰岩。 岩溶发育程度拟建工程场区分布的可溶性碳酸盐岩主要为三叠系下统大冶组（T1d）灰岩、二叠系下统栖霞组（P1q）灰岩及石炭系上统（C2）灰岩；分布里程桩号右CK4+330.6右CK4+688.7及桩号在右CK5+583.7右CK5+960.6段，各墩台

3、共揭露灰岩的钻孔有63个，有溶洞的钻孔14个，共揭露到溶洞23个，多为全填充，少数为无填充及个别半填充。充填物为硬塑状褐色、黄褐色粉质黏土夹灰岩碎、块石。溶洞发育情况详见表1.2.1.1-1。表1.2.1.1-1 溶洞情况一览表序号孔号基岩时代揭露灰岩厚度（m）溶洞顶板标高（m）溶洞底板标高（m）溶洞垂高（m）充填情况线岩溶率（%）1WQJz-16-Q2014P1q35.30-6.14-9.643.50全充填0.33P1q-10.84-13.943.10全充填P1q-14.34-18.043.70全充填P1q-26.34-27.841.50无充填2WQJz-16-Q2019P1q33.00-3

4、.59-4.591.00全充填0.03P1q-8.29-8.990.70无充填3WQJz-16-Q2021P1q34.00-2.56-3.360.80全充填0.02P1q-3.56-4.460.90全充填4WQJz-16-Q2022P1q33.60-4.05-5.051.00全充填0.035WQJz-16-Q2027P1q26.70-9.31-9.810.50全充填0.026WQJz-16-Q2032P1q39.00-0.34-7.347.00全充填0.187WQJz-16-Q2033P1q35.4-4.71-7.312.60全充填0.21P1q-8.51-13.314.80全充填8WQJz-

5、16-Q2034P1q36.10-2.69-6.694.00全充填0.119WQJz-16-Q2037P1q23.20-35.84-43.347.50全充填0.3210WQJz-16-Q2097T1d29.70-27.27-28.471.20无充填0.0411WQJz-16-Q2116T1d29.50-3.83-4.630.80全充填0.0312WQJz06-16-C2057T1d30.2-5.27-20.1714.90全充填0.4913WQJz06-16-C2204T1d31.4-6.99-10.593.6半填充10.314WQJz06-16-C2204T1d32.1-7.05-7.350.

6、3无充填12.3T1d-8.55-9.350.8无充填T1d-9.95-10.550.6全充填T1d-19.25-22.052.8无充填根据勘察报告，拟建场区三叠系下统大冶组（T1d）灰岩钻孔见洞率为22.2%，线岩溶率为4.7%；二叠系下统栖霞组（P1q）灰岩钻孔见洞率为75%，线岩溶率为12%；石炭系上统（C2）灰岩钻孔见洞率为33%，线岩溶率为5%。根据建筑地基基础设计规范（GB50007-2011）表6.2.2的规定，勘察场区在桩号右CK5+583.7右CK5+960.6m属于岩溶微发育区，桩号右CK4+488.5右CK4+688.7m属于岩溶强发育区，桩号右CK4+330.6右CK4

7、+488.5m属于岩溶强发育区；根据城市轨道交通岩土工程勘察规范（GB50307-2012）条文说明中表11的规定，勘察场区属于岩溶中等发育区。钻孔揭露溶洞均出现漏浆现象，表明场地范围内灰岩中岩溶裂隙有一定连通性。1.2.1.2 江国路站 岩溶发育区域地质情况拟建工程场地地貌单元上均属河流堆积平原，为长江级阶地，地形平坦，地表高程一般介于20.93m21.37m之间，相对高差0.44m，现状无坑塘发育。车站范围内下伏基岩为三叠系下统大冶组（T1d）灰岩。场地地下水类型有第四系上层滞水、孔隙承压水、岩溶裂隙水三种类型。其中，岩溶裂隙水主要赋存于下部三叠系下统大冶组（T1d）灰岩中，富水性受构造和

8、岩溶发育程度的控制，钻孔单位涌水量大小悬殊。 岩溶发育程度拟建江国路站分布的三叠系下统大冶组（T1d）灰岩（16b），属可溶性碳酸盐岩，本次勘察一共施工122个钻孔，其中有68个钻孔发现溶洞，该车站初勘共施工一个钻孔，未发现溶洞；综合初步勘察和详细勘察的勘察数据，本场地溶洞见洞率为55.74%，其中全充填溶洞58个，半充填溶洞40个，空洞33个，根据本次勘察资料，江国路站岩溶发育情况请见表1.2.1.2-2：表1.2.1.2 - 2 溶洞情况一览表序号孔号基岩时代揭露灰岩总厚度（m）溶洞顶板标高（m）溶洞底板标高（m）溶洞垂高（m）充填情况线岩溶率（%）见洞率（%）1WQJz06-16-C20

9、01T1d29.20-3.23-4.531.30全充填5.48（68122）100%=55.74%-7.23-7.530.30全充填2WQJz06-16-C2002T1d28.30-11.01-11.810.80无充填20.49-12.61-13.310.70无充填-16.11-16.710.60无充填-21.81-25.513.70半充填3WQJz06-16-C2005T1d22.60-5.99-7.691.70全充填37.17-8.79-13.694.90全充填-18.89-20.691.80无充填4WQJz06-16-C2006T1d26.70-10.53-11.030.50全充填40.

10、45-16.03-18.132.10无充填-21.93-30.138.20无充填5WQJz06-16-C2007T1d25.20-2.76-4.161.40全充填11.11-6.66-8.061.40全充填6WQJz06-16-C2008T1d23.60-6.76-7.660.90全充填19.49-9.56-11.562.00半充填-20.06-21.761.70半充填7WQJz06-16-C2010T1d25.40-3.23-5.832.60半充填20.47-10.03-12.632.60半充填8WQJz06-16-C2011T1d23.30-7.27-8.070.80无充填3.439WQJ

11、z06-16-C2014T1d25.70-5.60-8.603.00半充填11.6710WQJz06-16-C2017T1d27.40-8.68-9.681.00无充填3.6511WQJz06-16-C2018T1d27.40-8.82-9.821.00无充填3.6512WQJz06-16-C2041T1d28.40-13.16-14.961.80全充填6.3413WQJz06-16-C2042T1d38.00-8.50-10.602.10全充填5.53-28.30-32.103.80无充填14WQJz06-16-C2044T1d25.50-8.23-9.030.80半充填3.1415WQJz

12、06-16-C2048T1d24.30-8.36-10.662.30无充填9.4716WQJz06-16-C2051T1d17.90-11.69-14.893.20全充填17.8817WQJz06-16-C2052T1d19.10-10.24-12.342.10全充填15.18-16.54-17.340.80全充填18WQJz06-16-C2053T1d28.50-8.19-13.995.80半充填29.47-33.59-36.192.60半充填19WQJz06-16-C2054T1d26.30-9.03-9.530.50全充填1.9020WQJz06-16-C2055T1d22.10-9.6

13、8-11.281.60无充填21.27-13.78-16.883.10无充填21WQJz06-16-C2057T1d15.30-5.27-20.1714.90半充填97.3922WQJz06-16-C2060T1d18.60-11.59-12.991.40半充填84.95-22.99-37.3914.40无充填23WQJz06-16-C2061T1d25.9-2.70-5.602.90全充填52.12-8.70-9.801.10半充填-17.30-20.503.20半充填-23.50-25.001.50无充填-25.20-27.402.20无充填-27.60-30.202.60无充填24WQJ

14、z06-16-C2062T1d32.00-2.57-2.970.40全充填37.19-7.77-8.370.60全充填-25.47-36.3710.90无充填25WQJz06-16-C2063T1d29.30-2.02-4.822.80全充填9.5626WQJz06-16-C2065T1d31.20-3.12-3.720.60半充填1.9227WQJz06-16-C2066T1d23.600.06-6.646.70半充填28.3928WQJz06-16-C206829.20-6.70-7.701.00无充填3.4229WQJz06-16-C2069T1d30.10-2.91-3.911.00半

15、充填12.96-8.31-9.611.30半充填-11.11-11.710.60全充填-14.21-15.211.00全充填30WQJz06-16-C2070T1d26.60-2.84-3.841.00全充填15.79-4.84-7.042.20全充填-10.14-11.141.00全充填31WQJz06-16-C2103T1d24.10-7.31-8.911.60全充填6.6432WQJz06-16-C210525.00-22.47-24.472.00无充填8.0033WQJz06-16-C211125.80-11.30-12.701.40无充填5.4334WQJz06-16-C2114T1

16、d28.60-2.48-3.280.80全充填9.44-5.48-6.581.10全充填-8.38-9.180.80全充填35WQJz06-16-C2115T1d26.60-5.34-7.342.00全充填16.54-10.54-12.942.40全充填36WQJz06-16-C2116T1d25.50-3.80-8.905.10全充填20.0037WQJz06-16-C2119T1d26.30-1.97-3.571.60全充填30.80-6.07-6.470.40全充填-7.47-12.775.30全充填-25.07-25.870.80无充填38WQJz06-16-C2120T1d30.80

17、-2.43-3.230.80全充填9.42-23.93-26.032.10半充填39WQJz06-16-C212723.50-10.62-10.820.20无填充4.26-15.52-16.320.80无填充40WQJz06-16-C2134T1d25.80-18.95-19.750.80全充填3.1041WQJz06-16-C2136T1d16.90-11.42-12.421.00全充填5.9242WQJz06-16-C2143T1d27.00-7.47-7.970.50半充填1.8543WQJz06-16-C2146T1d33.00-5.35-7.852.50半充填7.5844WQJz06

18、-16-C2147T1d25.10-4.56-6.261.70全充填25.50-11.36-13.662.30半充填-23.16-25.562.40半充填45WQJz06-16-C2150T1d30.10-5.54-6.240.720全充填13.29-7.84-9.141.30无充填-25.54-27.542.00全充填46WQJz06-16-C2153T1d26.00-5.78-14.288.50半充填32.6947WQJz06-16-C2154T1d26.00-11.37-14.272.90全充填11.1548WQJz06-16-C2157T1d19.20-3.75-6.652.90全充填

19、50.52-6.85-13.656.80无充填49WQJz06-16-C2158T1d21.20-5.75-8.452.7全充填22.17-9.45-11.452.00无充填50WQJz06-16-C2159T1d22.80-5.69-9.493.80全充填25.88-10.89-12.992.10无充填51WQJz06-16-C2143T1d19.60-8.03-10.732.70半充填31.12-12.93-16.333.40无充填52WQJz06-16-C2161T1d24.70-3.71-8.314.60半充填26.72-16.71-18.111.40无充填-19.91-20.510.

20、60全充填53WQJz06-16-C2163T1d24.80-14.80-16.902.10半充填8.4754WQJz06-16-C2173T1d24.80-2.04-2.340.30全充填10.89-3.44-5.842.40全充填55WQJz06-16-C2179T1d18.60-4.67-5.470.80全充填19.89-6.27-7.571.30全充填-8.17-8.670.50全充填-9.47-10.571.10全充填56WQJz06-16-C2183T1d15.60-2.86-7.064.20全充填34.62-11.06-12.261.20全充填57WQJz06-16-C2193T

21、1d23.50-10.06-10.660.60无充填11.49-11.96-12.460.50全充填-14.26-15.861.60全充填58WQJz06-16-C2194T1d26.30-11.08-11.380.30半充填9.89-22.89-24.582.30半充填59WQJz06-16-C2199T1d18.60-15.88-23.988.10半充填43.5560WQJz06-16-C2122T1d26.80-6.65-8.852.20半充填25.00-14.05-16.152.10半充填-18.15-20.552.40半充填61WQJz06-16-C2123T1d30.20-6.49

22、-11.094.60半充填15.2362WQJz06-16-C2125T1d27.10-6.39-11.294.9半充填22.14-17.19-18.291.10无充填63WQJz06-16-C2176T1d27.30-2.17-4.772.60全充填32.97-5.17-6.371.20无充填-9.07-11.272.20全充填-14.17-17.173.00无充填64WQJz06-16-C2177T1d25.30-2.3-3.41.10全充填47.08-8.5-11.893.40半充填-16.8-22.305.50半充填-26.09-28.001.91半充填65WQJz06-16-C218

23、2T1d35.40-1.96-3.161.20全充填3.3966WQJz06-16-C2186T1d30.00-2.24-3.741.50全充填23.67-4.74-6.241.50全充填-10.24-14.344.10半充填67WQJz06-16-C2190T1d27.4-8.48-12.383.90无充填14.2368WQJz06-16-C2208T1d32.1-10.96-11.961.00半充填3.12根据上表可知，拟建场区三叠系下统大冶组（T1d）灰岩分布段钻孔见洞率为55.74%，根据建筑地基基础设计规范（GB50007-2011）表6.6.2的规定， 勘察场区灰岩分布段属于岩溶强

24、发育区；根据城市轨道交通岩土工程勘察规范（GB50307-2012）条文说明中表11的规定，勘察场区灰岩分布段属于岩溶中等发育区。勘察场区灰岩分布段钻孔揭露溶洞大多出现漏浆现象，表明场地范围内灰岩中岩溶裂隙连通性较好。1.2.2水文地质条件工程场区地处河流堆积平原地貌单元（相当于长江级阶地）。场地内地表水不发育，主要为大气降水形成的面流，向低洼处汇入地下市政排水管网，暴雨时场地内地表会形成间歇性积水。工程场区西北侧为长江，距长江约2.33.0km，根据长江宜昌关水文资料：宜昌地区的长江最高洪水位为29.73m(吴淞高程系统，1954.8.18)，最低枯水位8.87m，水位升降幅度20.86m，

25、多年平均水位18.97m。按场地地下水赋存条件，主要为第四系上层滞水、孔隙承压水、碎屑岩裂隙水、岩溶裂隙水四种类型。第四系上层滞水主要赋存于（1-1）杂填土、（1-2）素填土中，主要接受地表水与大气降水补给。上层滞水为墩台基槽积水的主要来源，墩台基础开挖时墩台四周应采取截排水措施，同时可采用坑内明沟导流，集中予以排出。第四系孔隙承压水为本区（级阶地）主要地下水，主要赋存于第四系冲积砂性土及黏性土与砂性土互层中，含水层厚度一般3.90m26.50m。本次勘察实测地下水位埋深3.00m4.50m，相应标高15.81m18.22m。场区内孔隙承压水水头较高，为场区内的主要含水层，但含水层上部有一定厚度的黏性土相对隔水层，且墩台基础开挖深度小于5.0m，因此孔隙承压水对墩台基础开挖影响较小；拟建物拟采用桩基础，孔隙承压水对桩基施