武汉琴断口小桥岩溶发育特征及岩溶处理  

Development and Treatment of Karst Rock Cavities in Qinduankou in Wuhan

作　　者：王辉 WANG Hui(Wuhan Municipal Flood Control Design and Investigation Institute Co.Ltd.,Wuhan 430050)

机构地区：[1]武汉市城市防洪勘测设计院,武汉430050

出　　处：《土工基础》2024年第5期828-831,共4页Soil Engineering and Foundation

摘　　要：为查明琴断口小桥岩溶发育特征,对0#墩、1#墩岩溶带进行了统计和分析研究,结果表明:琴断口小桥岩溶位于为大桥倒转向斜北翼,属于L2大桥条带,可溶性岩为二叠系栖霞组(P_(1q))灰岩;钻孔遇洞率36.8%,其中4个钻孔发育3~6个溶洞,呈串珠状发育,占57%,最大线溶率44.12%,岩溶强发育,溶洞发育桩位均集中在右幅;岩溶发育带厚15 m;与以往发现大桥条件岩溶发育带相比较,岩溶带埋深更大,溶洞底板在基岩面下的埋深大部分9.80~14.7 m;埋藏型岩溶地质结构是一种新型地质结构,非可溶性岩为二叠系下统栖霞组(P_(1q))炭质页岩。根据桩基础工程特点及地质条件,采用充填注浆对溶洞进行了处理,施工中采用探灌结合,发挥钻孔的最大经济效应,取得良好的效果。To identify the karst rock cavity development at Xiaoqiao in Qinduankou,the statistical as well as the analytical studies are conducted at Pier 0 and Pier 1,respectively.The results showed that the karst formation at Xiaoqiao,Qinduankou is at the north side of the proposed bridge,which belongs to the L2 bridge zone.The soluble bedrock is the Permian Qixia Formation (P_(1q)) limestone;The probability of encountering karst rock cavities in boreholes is 36.8%,among which 4 boreholes have developed 3-6 karst cavities in a string shaped development,accounting for the 57%of the entire coring length.The maximum linear karst rate is 44.12%,and the karst is therefore strongly developed.The of karst pinnacles are concentrated in the right side the area.The thickness of the karst development zone is 15 meters;Compared with the previously discovered karst development zone under bridge conditions,the overburden soil thickness in this area is greater,and the embedment depth of the bottom plate of the karst cavity below the bedrock surface is mostly 9.80-14.7m;②The quasi embedded karst geological structure is a new geological structure,and the non-soluble bedrock is the carbonaceous shale of the Lower Permian Qixia Formation(P_(1q)).According to the engineering characteristics and geological conditions of the proposed pile foundation,the karst cave was treated by compaction grout.During the construction,the combination of exploration grouting is used to maximize the economic effect of the geotechnical drilling.

关 键 词：琴断口 岩溶地质结构 溶洞 探灌结合 

分 类 号：TU457[建筑科学—岩土工程]