黄河峡谷地貌拉加断裂工程特性及形成机理  

Study on the present situation and mechanism of laga fault in Yellow River Canyon landform

作　　者：窦增宁 Dou Zengning(Qinghai Transportation Planning Design and Research Institute Co.,Ltd,xining 810008,China)

机构地区：[1]青海省交通规划设计研究院有限公司,西宁810008

出　　处：《青海交通科技》2022年第4期75-80,87,共7页Qinghai Transportation Science and Technology

摘　　要：本项研究以拉加断裂影响较大的区域拉加镇地区作为主要研究对象,通过调绘、物探、钻探、试验等手段详细分析该区域断裂现状、特征与形成机理,结果表明,拉加断裂整体走向北东,平面上呈反“S”状,倾向北西,倾角40°~50°,北东段在泽库县境内被日月山断裂所截,南西段在大武镇境内被西科河—军牧场—大武断裂截断,整体长约140 km,属于当青弧形构造的东翼,因而受到北西—南东向的挤压作用力与北东—南西走滑作用力,继而在三叠系与新近系沉积的不整合接触界线处形成一倾向北西的逆断层、兼具左行运动特征。研究表明该断裂宽度约达518 m,视电阻率一般约300~430Ωm,代表性产状:320°<45°,其中,断层破碎带处天然抗压强度为0.7~1.12 Mpa。该理论结果可为拉加镇区域工程建设提供数据参考和实际指导意义。This study takes the Lajia-zhen area,which is a large area affected by the Lajia-Zhen fault,as the main research object.By means of mapping,geophysical exploration,drilling and testing,the present situation,characteristics and formation mechanism of the fault in this region are analyzed in detail.It is concluded that the overall strike of the laga fault is northeast,with an inverse“s”shape on the plane,a dip angle of 40~50°,and the northeast section is intercepted by the Riyueshan fault in Zeku County,the southwest section is cut off by xikehe Junchang Dawu fault in Dawu Town,with an overall length of about 140km.It belongs to the east wing of Dangqing arc structure.Therefore,it is subjected to the NW-SE compressional force and the NE-SW strike-slip force.and then forms a NW trending reverse fault at the unconformity contact boundary between Triassic and Neogene deposits,which has the characteristics of sinistral movement.The fracture width is about 518 m after exploration.The apparent resistivity is generally about 300~430Ωm,and the representative occurrence is 320°<45°.The natural compressive strength at the fault fracture zone is 0.7~1.12 MPa.The theoretical results can provide data reference and practical guidance for regional engineering construction in Laga Town.

关 键 词：断层特征 形成机理 地质勘察 

分 类 号：U412.2[交通运输工程—道路与铁道工程]