沧口断裂断层泥膨胀机理研究  

The Study on Expansion Mechanism of the Gouge of Cangkou Fault

作　　者：冷传旭 李学专 孙玺 邵铖 王晔 LENG Chuanxu;LI Xuezhuan;SUN Xi;SHAO Cheng;WANG Ye(Qingdao Surveying&Mapping Institute,Qingdao 266032,China;Geotechnical Engineering Technology Center of Qingdao,Qingdao 266032,China;Qingdao Haiboer Construction Engineering Testing Co.,Ltd.,Qingdao 266032,China)

机构地区：[1]青岛市勘察测绘研究院,山东青岛266032 [2]青岛岩土工程技术研究中心,山东青岛266032 [3]青岛海泊尔建设工程检测有限公司,山东青岛266032

出　　处：《城市勘测》2022年第6期199-203,共5页Urban Geotechnical Investigation & Surveying

基　　金：青岛市城市地质调查项目(ZFCG2019001542)。

摘　　要：在青岛市城市地质调查中钻探获得的沧口断裂断层泥具有明显的膨胀性,为查明断层泥膨胀机理,对比测试了沧口断裂主断面处的断层泥和临近主断面处的泥质断层角砾岩的自由膨胀率、黏土矿物成分,并采用扫描电镜观测和定量分析其微组构特征。通过分析研究,揭示了断层泥的膨胀特性和膨胀机理:①沧口断裂断层泥自由膨胀率为92%~120%,属强膨胀,泥质断层角砾岩自由膨胀率为12%~55%,为无膨胀性或弱膨胀;②沧口断裂断层泥中黏土矿物主要为伊/蒙混层黏土矿物,含量为25%~48%,是主要的膨胀性黏土矿物;③强膨胀的断层泥具有大量伊/蒙混层黏土矿物围绕碎屑矿物半定向排列的微观结构,孔隙分形维数也体现出断层泥孔隙具有明显的自相似性,反映了在多期次压扭性构造应力作用下,断层泥形成了特殊的微观结构,这种微观结构特征增强了断层泥的膨胀潜势。The Cangkou fault gouge obtained by drilling in the Qingdao urban geological survey has obvious expansion.In order to find out the expansion mechanism of the fault gouge,the fault gouge at the main section of Cangkou fault and the argillaceous fault near the main section were compared and tested.The free expansion rate and clay mineral composition of the breccia were observed and quantitatively analyzed by scanning electron microscope.Through analysis and research,the expansion characteristics and expansion mechanism of the fault gouge are revealed:①The free expansion rate of the fault gouge in Cangkou fault is 92%~120%,which is a strong expansion,and the free expansion rate of the argillaceous fault breccia is 12%~12%~55%,which is no expansion or weak expansion;②The clay minerals in the fault gouge of Cangkou fault are mainly Illite-smectite mixed-layer clay mineral,with a content of 25%to 48%,which are the main expansive clay minerals;③The strongly expansive fault gouge has a microstructure in which a large number of Illite-smectite mixed-layer clay mineral are arranged semi-directionally around the clastic minerals.The pore fractal dimension also shows that the fault gouge pores have obvious self-similarity,reflecting the multi-stage compressive torsion.Under the action of tectonic stress,the fault gouge forms a special microstructure,which enhances the expansion potential of the fault gouge.

关 键 词：沧口断裂 断层泥 膨胀机理 伊/蒙混层黏土矿物 微观结构 分形维数 

分 类 号：TU443[建筑科学—岩土工程]