摘要
佛山市南海区大沥镇黄岐海北片区地处珠江三角洲北部广花盆地边缘地带,第四纪软土、砂土以及隐伏岩溶发育,早期因区内人类工程活动强烈,诱发了群发性岩溶地面塌陷。文章在分析地质环境概况的基础上,研究了区内岩溶地面塌陷的发育特征和成因机理,认为溶洞土洞发育是先决条件,导水断裂发育是必要条件,因施工引发的地下水位下降是主要触发因素,F1断裂带附近仍具备发生岩溶塌陷的可能性,控制地下水水位标高在-3.0 m以内,地下水水位波动范围在1.5 m以内,可以大幅度降低岩溶塌陷发生概率,可以以此作为预警报警阈值。研究结果可以为佛山市城镇化建设过程中岩溶地面塌陷防治提供依据,也可以为其他类似地区防灾减灾提供借鉴。
The study area is located in the eastern part of Michong village, north Huangqi community, Dali town,Nanhai district, Foshan City. Situated in the southern margin of Guanghua basin and the transitional zone between hilly region and plain region in the northern Pearl River Delta, the area is flat in terrain and convenient by transportation.The study area is characterized by wet spring, long hot summer, warm autumn and winter without frost, with south subtropical monsoon climate. The annual average temperature in this area is 21.9 °C with an annual average precipitation of 1,400-1,900 mm and a multi-year average of 1,613.5 mm. Rainfall is concentrated from April to September, accounting for about 80% of the whole year, and the multi-year average evaporation is 1,153 mm, which is generally less than the rainfall.In recent years, intensive human engineering activities such as the construction of high-speed rail, underground engineering of subway and pile foundation construction in the area have induced a large number of karst ground collapses and ground subsidence. Especially from February 2008 to September 2009, the affected area reached 1.2 km2,and 15 karst ground collapses occurred successively in the area, with the maximum land subsidence amounting to87 cm. Damage, in different degrees, to Huangqi No.2 Middle School, DHL logistics Center, some factories and residential buildings was caused by the collapse and subsidence, in which more than 2,000 people were directly affected, and the direct economic loss was nearly 200 million yuan.The only exposed stratum in the study area is Holocene Guizhou formation(Qhg), but the hidden strata include lower Carboniferous ShiDengzi formation(C1s) and Ceshui formation(C1c), upper Carboniferous Hutian formation(C2h), lower Jurassic Jinji formation(J1j), upper Cretaceous Dayangshan formation(K2dl), and Quaternary residual layers(Qel). There is one fault zone with 5 groups in the study area, belonging to Shabei fault zone extending from the south-west direction of the fault zone.
作者
张宗胜
ZHANG Zongsheng(Foshan Geological Bureau of Guangdong Province,Foshan,Guangdong 528000,China)
出处
《中国岩溶》
CAS
CSCD
北大核心
2022年第6期880-894,共15页
Carsologica Sinica
基金
佛山市南海区大沥镇黄岐海北片区地质灾害勘查(X20090203)
佛山市城市地质调查(2010204)
佛山市地质灾害监测预警与应急指挥平台(X20190436)。
关键词
岩溶地面塌陷
成因机制
趋势分析
施工降水
导水断裂
佛山市
karst collapse
mechanism
trend analysis
construction precipitation
water-conducting fracture
Foshan city
