人民长江
人民長江
인민장강
YANGTZE RIVER
2014年
14期
43-46
,共4页
苗朝%沈军辉%李文纲%魏伟%陈卫东
苗朝%瀋軍輝%李文綱%魏偉%陳衛東
묘조%침군휘%리문강%위위%진위동
花岗岩%辉绿岩%岩体结构%改造特征差异%工程地质特性
花崗巖%輝綠巖%巖體結構%改造特徵差異%工程地質特性
화강암%휘록암%암체결구%개조특정차이%공정지질특성
granite%dolerite dikes%rock mass structure%reformation characteristics difference%engineering geological charac-teristics
针对大岗山高拱坝花岗岩和侵入辉绿岩脉的后期改造特征,通过详细调研和室内外试验,探讨了坝区岩体在后期改造作用下的岩体结构类型、断层发育特征和蚀变特征的差异性,并研究其对岩体工程地质特性及构造格局的影响。研究表明:花岗岩岩体结构类型以块状结构为主,而辉绿岩以性状较差的碎裂结构和镶嵌结构为主;坝区断层以岩脉式断层占主导地位,占坝区断层的70%,规模较大,且构造挤压破碎和绿泥石化严重,性状较差。辉绿岩脉后期较花岗岩蚀变强烈,生成了较多的绿泥石黏土矿物,造成其波速和变形模量的降低幅度都较花岗岩大。辉绿岩的强烈蚀变改造形成坝区岩脉式断层软弱结构面的构造格局。
針對大崗山高拱壩花崗巖和侵入輝綠巖脈的後期改造特徵,通過詳細調研和室內外試驗,探討瞭壩區巖體在後期改造作用下的巖體結構類型、斷層髮育特徵和蝕變特徵的差異性,併研究其對巖體工程地質特性及構造格跼的影響。研究錶明:花崗巖巖體結構類型以塊狀結構為主,而輝綠巖以性狀較差的碎裂結構和鑲嵌結構為主;壩區斷層以巖脈式斷層佔主導地位,佔壩區斷層的70%,規模較大,且構造擠壓破碎和綠泥石化嚴重,性狀較差。輝綠巖脈後期較花崗巖蝕變彊烈,生成瞭較多的綠泥石黏土礦物,造成其波速和變形模量的降低幅度都較花崗巖大。輝綠巖的彊烈蝕變改造形成壩區巖脈式斷層軟弱結構麵的構造格跼。
침대대강산고공패화강암화침입휘록암맥적후기개조특정,통과상세조연화실내외시험,탐토료패구암체재후기개조작용하적암체결구류형、단층발육특정화식변특정적차이성,병연구기대암체공정지질특성급구조격국적영향。연구표명:화강암암체결구류형이괴상결구위주,이휘록암이성상교차적쇄렬결구화양감결구위주;패구단층이암맥식단층점주도지위,점패구단층적70%,규모교대,차구조제압파쇄화록니석화엄중,성상교차。휘록암맥후기교화강암식변강렬,생성료교다적록니석점토광물,조성기파속화변형모량적강저폭도도교화강암대。휘록암적강렬식변개조형성패구암맥식단층연약결구면적구조격국。
According to the reformation characteristics of granite and intruded dolerite dikes in the dam area of Dagangshan Hydropower Station, by detail investigation, indoor and field tests, this paper studied the structure classification of rock mass, fault development characteristics and the alteration difference of rock mass in the dam area after post-reformation, as well as its influence on engineering geological characteristics and tectonic framework. The study result revealed that the main rock structure of granite is a block one while the main rock structures of dolerite are broken and intercalation ones with poor geological engineer-ing property, the rock dyke fault is the dominant fault in the dam area with large proportion of about 70%, squeezing and frac-tured structure with severe chloritization and poor engineering property. The diabase alteration is more intensive than granite in later period and generates much chlorite clay mineral, which results that the wave velocity and deformation modulus of diabase dikes decrease more than that of granite. Strong alteration of diabase dikes has formed the soft structural faces of rock-dyke faults.