Karst development characteristics and karst cave treatment technology of a large-scale engineering site in Longgang
-
摘要: 为深入研究岩溶发育特征对桩基施工的影响，基于勘察钻探资料和现场桩基施工情况，文章对深圳龙岗区某超高层大型工程场地岩溶发育规律及空间展布特征进行精细描述，并总结归纳溶洞处理原则和施工措施。结果表明：研究区地下岩溶空间形态复杂，发育主要表现为溶蚀裂隙、溶沟、溶槽，其沿层面、节理方向的溶隙较为发育，约34%的钻孔揭露溶洞数量大于3个，溶洞垂向发育密集，发育类型主要为中小型溶洞；溶洞以全填充为主、半填充次之，其溶洞充填物主要为含角砾粉质黏土、含砂黏土，溶洞顶板埋深平均为32.2 m，顶板厚度平均为2.2 m；灰岩埋深较大，顶板厚度较薄，属深覆盖岩溶区；岩溶发育特征主要受地层岩性、地质构造、水文地质条件等因素综合控制，且在垂向上具有明显的分层性，其岩溶强发育带主要位于地表以下埋深25~40 m之间。针对岩溶区溶洞发育的复杂性，桩基采用“超前注浆预处理+水泥拌土或C15混凝土形成人工造壁”方案处理溶洞，在保证施工质量的同时有效节约成本。Abstract:
The geological structure of Shenzhen is complex, characterized by fault structures and regional erosion, which have led to significant karst development. Karst is roughly distributed in a northeast-trending, strip-like pattern. The study area is located at the Ecological Intelligence Valley Headquarters Base, part of the Dayun Shenzhen-Hong Kong International Science and Education City in Longgang district, Shenzhen. This area comprises multiple towers, their podiums, and basements, with a maximum building height of 188 meters. The building includes 41 floors above ground and two underground floors, and represents the primary zone with karst development. According to survey and drilling data, the geological strata in the study area are mainly composed of the Quaternary (Q) soil layer and the rock layer of lower Carboniferous Water Measurement Formation (C1c). A total of 399 boreholes were drilled on site, including 250 boreholes exposing soluble limestone layers and 173 boreholes exposing karst caves. The porosity rate of these boreholes is 69.2%, and the linear karst rate is 26.5%, indicating a region with intense karst development. To further investigate the impact of karst development on pile foundation construction, this study utilized survey drilling data and addressed the challenges posed by karst caves during on-site pile foundation construction along with their corresponding solutions. A detailed description of the karst development patterns and spatial distribution characteristics of the study area site was conducted, and the principles of karst cave treatment and related construction measures were summarized. The results showed that, (1) The underground karst space in the study area exhibits a complex morphology, mainly characterized by dissolution fissures, dissolution channels, and dissolution troughs. Dissolution fissures along the bedding planes and joint directions are relatively well developed. About 34% of the boreholes revealed more than three karst caves, and about 83.6% of the karst caves were less than five meters in height, with an average height of 3.03 m. The vertical development of karst caves is dense, with mainly small- and medium-sized caves being the predominant types. (2) The karst caves in the study area are mainly filled, followed by semi-filled caves. The filling materials primarily consist of silty clay containing angular gravel and sandy clay. The average burial depth of the cave roofs is 32.2 m, with an average roof thickness of 2.2 m. The limestone burial depth is relatively large, belonging to a deep covered karst area. (3) The development characteristics of karst in the study area are mainly controlled by factors such as lithology, geological structure, and hydrogeological conditions. The karst exhibits distinct vertical layering, with its development occurring at depths of 25 m to 80 m below the surface. The zone of strong karst development is mainly between 25 m and 40 m in depth. Due to the intense development of shallow karst, caves cannot be avoided, and the thickness of the cave roof is thin, resulting in insufficient bearing capacity. Therefore, pile foundation construction must cross the strongly developed zone of shallow karst to reach the stable bearing layer of limestone. (4) To address the complex development of karst caves in the study area, a combination of drilled pile foundations and raft foundations was employed in building foundation, with limestone serving as the bearing layer. The pile foundation treatment involves an "advanced grouting pretreatment plus artificial wall formation using cement mixed with soil or C15 concrete" approach to stabilize the karst caves. This method has yielded favorable results during actual construction process, with all core drilling tests of the foundation piles classified as Class I piles, ensuring construction quality while also reducing costs. -
图 1 典型工程地质剖面图(比例尺1∶500)
Figure 1. Typical engineering geological profile (scale 1∶500)
图 7 深圳可溶性岩与构造分布示意图(比例尺1∶
50000 )Figure 7. Schematic diagram of soluble rocks and structural distribution in Shenzhen (scale 1∶
50,000 )
图 8 不同埋深溶洞模型平面图(比例尺1∶500)
Figure 8. Plan view of karst cave models with different burial depths (scale 1∶500)
-
[1] 郭纯青, 王莉, 王洪涛. 中国岩溶生态地质研究[J]. 生态环境, 2005, 14(2): 275-281. doi: 10.3969/j.issn.1674-5906.2005.02.030Guo Chunqing, Wang Li, Wang Hongtao. The research of karst ecological geology in China[J]. Ecology and Environment, 2005, 14(2): 275-281. doi: 10.3969/j.issn.1674-5906.2005.02.030 [2] 杨富山. 岩溶区桩基承载特性及施工技术研究[D]. 兰州: 兰州交通大学, 2018.YANG Fushan. The bearing characteristic and construction technique research of pile foundation in karst area [D]. Lanzhou: Lanzhou Jiaotong University, 2018. [3] 王宁, 杨春利, 赵英萍, 王莉婵. 某大型工程场地岩溶发育特征及工程地质条件评价[J]. 地震工程学报, 2016, 38(S2): 351-355,361. doi: 10.3969/j.issn.1000-0844.2016.Supp.2.0351Wang Ning, Yang Chunli, Zhao Yingping, Wang Lichan. Distribution of karst and engineering geology conditions on a project site[J]. China Earthquake Engineering Journal, 2016, 38(S2): 351-355,361. doi: 10.3969/j.issn.1000-0844.2016.Supp.2.0351 [4] 郭纯青, 李志宇, 杨军, 田西昭, 田月明, 胡君春. 云南某工程建设场地岩溶分布与形成机制[J]. 地质与勘探, 2015, 51(5): 984-992. doi: 10.13712/j.cnki.dzykt.2015.05.020Guo Chunqing, Li Zhiyu, Yang Jun, Tian Xizhao, Tian Yueming, Hu Junchun. Distribution and formation mechanism of karst on a project site in Yunnan Province[J]. Geology and Exploration, 2015, 51(5): 984-992. doi: 10.13712/j.cnki.dzykt.2015.05.020 [5] 杜海龙, 贺茉莉, 罗小斌, 宾斌, 赵铁军. 岩溶地区某广场钻孔灌注桩基础补强加固设计与新技术[J]. 中国岩溶, 2019, 38(4): 600-606. doi: 10.11932/karst20190419Du Hailiong, He Moli, Luo Xiaobin, Bin Bin, Zhao Tiejun. A new technology of reinforcement by cast-in place pile foundation in karst areas[J]. Carsologica Sinica, 2019, 38(4): 600-606. doi: 10.11932/karst20190419 [6] 曹贤发, 刘玉康, 刘之葵, 张炳辉. 基于强溶蚀带特征的地基岩溶发育程度评价方法[J]. 中国岩溶, 2020, 39(4): 577-583. doi: 10.11932/karst20200413Cao Xianfa, Liu Yukang, Liu Zhikui, Zhang Binghui. Evaluation method of development degree based on features of intense dissolution layer[J]. Carsologica Sinica, 2020, 39(4): 577-583. doi: 10.11932/karst20200413 [7] 刘动, 林沛元, 陈贤颖, 黄胜, 马保松. 深圳岩溶空间发育规律统计分析[J]. 岩土力学, 2022, 43(7): 1899-1912.Liu Dong, Lin Peiyuan, Chen Xianying, Huang Sheng, Ma Baosong. Statistical analysis of karst spatial distribution in Shenzhen[J]. Rock and Soil Mechanics, 2022, 43(7): 1899-1912. [8] 蒙彦, 郑小战, 雷明堂, 李卓骏, 贾龙, 潘宗源. 珠三角地区岩溶分布特征及发育规律[J]. 中国岩溶, 2019, 38(5): 746-751. doi: 10.11932/karst20190510Meng Yan, Zheng Xiaozhan, Lei Mingtang, Li Zhuojun, Jia Long, Pan Zongyuan. Karst distribution and development in the Pearl River Delta[J]. Carsologica Sinica, 2019, 38(5): 746-751. doi: 10.11932/karst20190510 [9] 王楷翔, 王晓涛, 宫亮, 黄丹. 考虑时空效应的岩溶隧道围岩稳定性分析[J]. 中国岩溶, 2024, 43(3): 717-726. doi: 10.11932/karst20240311Wang Kaixiang, Wang Xiaotao, Gong Liang, Huang Dan. Stability analysis of karst tunnel surrounding rock considering spatiotemporal effects[J]. Carsologica Sinica, 2024, 43(3): 717-726. doi: 10.11932/karst20240311 [10] 郑伟国, 谢毓才, 薛绪标. 岩溶地区桩基选型浅谈[J]. 岩土工程学报, 2011, 33(S2): 404-407.Zheng Weiguo, Xie Yucai, Xue Xubiao. Selection of pile foundations in karst areas[J]. Chinese Journal of Geotechnical Engineering, 2011, 33(S2): 404-407. [11] 李想, 尹骥, 卫佳琦, 韦马季. 深覆盖岩溶地区高层建筑桩基优化实践[J]. 中国岩溶, 2019, 38(4): 591-599. doi: 10.11932/karst20190418Li Xiang, Yin Ji, Wei Jiaqi, Wei Maji. Optimization of pile foundation for high-rise buildings in deep-covered karst areas[J]. Carsologica Sinica, 2019, 38(4): 591-599. doi: 10.11932/karst20190418 [12] 石振明, 沈丹祎, 彭铭, 林杰豹. 岩溶地区桩基施工溶洞处理技术: 以吉安永和大桥桩基施工为例[J]. 工程地质学报, 2015, 23(6): 1160-1167. doi: 10.13544/j.cnki.jeg.2015.06.017Shi Zhenming, Shen Danyi, Peng Ming, Lin Jiebao. Karst cave disposing technology for pile foundation construction, illustrated with Yonghe bridge in Ji’an[J]. Journal of Engineering Geology, 2015, 23(6): 1160-1167. doi: 10.13544/j.cnki.jeg.2015.06.017 [13] 李清明, 徐腾飞, 李勇国, 梅年峰, 黄勐. 深圳地铁8号线岩溶发育特征及施工处理措施[J]. 桂林理工大学学报, 2017, 37(3): 405-411. doi: 10.3969/j.issn.1674-9057.2017.03.002Li Qingming, Xu Tengfei, Li Yongguo, Mei Nianfeng, Huang Meng. Karst characteristics and construction measures in Shenzhen Metro Line 8[J]. Journal of Guilin University of Technology, 2017, 37(3): 405-411. doi: 10.3969/j.issn.1674-9057.2017.03.002 [14] 吕耀成, 李钰强, 张富荣, 巨广宏. 莲花台水电站岩溶发育特征及工程意义[J]. 中国岩溶, 2019, 38(4): 502-507.Lyu Yaocheng, Li Yuqiang, Zhang Furong, Ju Guanghong. Karst features of the Lianhuatai hydropower station and engineering significance[J]. Carsologica Sinica, 2019, 38(4): 502-507. [15] GB 50007-2011 建筑地基基础设计规范[S].GB 50007-2011 Code for design of building foundation [S]. [16] 张伊飞. 龙岗岩溶场区地震波数值模拟及层析成像研究[D]. 成都: 西南交通大学, 2023.Zhang Yifei. Study on seismic wave numerical simulation and tomography in Longgang karst area [D]. Chengdu: Southwest Jiaotong University, 2023. [17] 赵少忠, 黄鑫, 许振浩, 李明海. 齐岳山隧道岩溶发育特征与溶洞处治技术研究[J]. 隧道建设(中英文), 2022, 42(7): 1289. doi: 10.3973/j.issn.2096-4498.2022.07.017Zhao Shaozhong, Huang Xin, Xu Zhenhao, Li Minghai. Development characteristics and treatment techniques of karst caves in Qiyueshan tunnel[J]. Tunnel Construction, 2022, 42(7): 1289. doi: 10.3973/j.issn.2096-4498.2022.07.017 [18] 姜文, 柏道远, 尹欧, 杨帆, 彭祖武, 钟响, 李彬, 李银敏. 湘中灰山港–煤炭坝地区岩溶发育特征及其构造控制[J]. 中国岩溶, 2022, 41(1): 1-12.Jiang Wen, Bai Daoyuan, Yin Ou, Yang Fan, Peng Zuwu, Zhong Xiang, Li Bin, Li Yinmin. Characteristics of karst development and its structural control in the Huishangang-Meitanba area of central Hunan[J]. Carsologica Sinica, 2022, 41(1): 1-12. [19] 罗小杰, 张三定, 沈建. 武汉地区表层岩溶带发育特征[J]. 中国岩溶, 2018, 37(5): 650-658.Luo Xiaojie, Zhang Sanding, Shen Jian. Development characteristics of the epikarst zone in Wuhan area[J]. Carsologica Sinica, 2018, 37(5): 650-658. [20] 贺建清, 喻畅英, 肖兰, 高文华. 基于上限定理确定岩溶区桩端极限承载力及其下伏溶洞顶板安全厚度[J]. 自然灾害学报, 2017, 26(2): 47-52. doi: 10.13577/j.jnd.2017.0206He Jianqing, Yu Changying, Xiao Lan, Gao Wenhua. Determination of ultimate bearing capacity of pile tip and safety thickness of cave roofs under pile tip in karst area based on upper bound theorem[J]. Journal of Natural Disasters, 2017, 26(2): 47-52. doi: 10.13577/j.jnd.2017.0206 [21] 覃夏南, 张敏, 吴明亮, 唐灵. 广东惠州岩溶分布特征及地质意义[J]. 矿产勘查, 2023, 14(12): 2288-2300.Qin Xianan, Zhang Min, Wu Mingliang, Tang ling. Distribution characteristics and geological significance of karst in Huizhou, Guangdong Province[J]. Mineral Exploration, 2023, 14(12): 2288-2300. [22] 梁永国, 程小勇. 深圳龙岗区葵涌岩溶地质勘查[J]. 岩土工程界, 2009, 12(7): 23-26. -
下载:
点击查看大图
图(13)
计量
- 文章访问数: 5
- HTML浏览量: 2
- PDF下载量: 0
- 被引次数: 0
