岩石力学与工程学报
巖石力學與工程學報
암석역학여공정학보
CHINESE JOURNAL OF ROCK MECHANICS AND ENGINEERING
2013年
11期
2235-2241
,共7页
刘宁%张春生%褚卫江%吴旭敏
劉寧%張春生%褚衛江%吳旭敏
류저%장춘생%저위강%오욱민
岩石力学%开挖损伤区%应力状态%节理%损伤程度%大理岩
巖石力學%開挖損傷區%應力狀態%節理%損傷程度%大理巖
암석역학%개알손상구%응력상태%절리%손상정도%대리암
rock mechanics%excavation damaged zone(EDZ)%stress state%joint%damage degree%marble
在高应力条件下,岩体强度和应力之间的尖锐矛盾将导致围岩出现损伤,损伤是不同应力条件下围岩状态的直接体现。利用声波检测和钻孔电视对锦屏二级深埋引水隧洞的一典型断面进行全断面测试,声波测试结果显示,断面上低波速带断面形态呈不对称状,与断面应力分布也并不完全对应。在每个声波钻孔中补充钻孔电视,对破裂发育深度和围岩内部实际构造特征有了更直观的认识。为对损伤区特性进行更加准确的描述,利用FLAC3D计算在洞周不同位置处关键点的应力路径,对关键点的应力状态进行分析。在UDEC泰森多边形离散的基础上增加对于节理的描述,分析节理对损伤区分布的影响,模拟结果表明,节理的存在改变了隧洞开挖后洞周的应力分布,从而导致围岩破损和破坏区域的差异。最后,借助于颗粒流程序PFC对隧洞开挖后围岩的损伤区进行模拟,所揭示出的损伤局部化特征和损伤区、破裂区分布特征与现场实际具有很好的一致性。
在高應力條件下,巖體彊度和應力之間的尖銳矛盾將導緻圍巖齣現損傷,損傷是不同應力條件下圍巖狀態的直接體現。利用聲波檢測和鑽孔電視對錦屏二級深埋引水隧洞的一典型斷麵進行全斷麵測試,聲波測試結果顯示,斷麵上低波速帶斷麵形態呈不對稱狀,與斷麵應力分佈也併不完全對應。在每箇聲波鑽孔中補充鑽孔電視,對破裂髮育深度和圍巖內部實際構造特徵有瞭更直觀的認識。為對損傷區特性進行更加準確的描述,利用FLAC3D計算在洞週不同位置處關鍵點的應力路徑,對關鍵點的應力狀態進行分析。在UDEC泰森多邊形離散的基礎上增加對于節理的描述,分析節理對損傷區分佈的影響,模擬結果錶明,節理的存在改變瞭隧洞開挖後洞週的應力分佈,從而導緻圍巖破損和破壞區域的差異。最後,藉助于顆粒流程序PFC對隧洞開挖後圍巖的損傷區進行模擬,所揭示齣的損傷跼部化特徵和損傷區、破裂區分佈特徵與現場實際具有很好的一緻性。
재고응력조건하,암체강도화응력지간적첨예모순장도치위암출현손상,손상시불동응력조건하위암상태적직접체현。이용성파검측화찬공전시대금병이급심매인수수동적일전형단면진행전단면측시,성파측시결과현시,단면상저파속대단면형태정불대칭상,여단면응력분포야병불완전대응。재매개성파찬공중보충찬공전시,대파렬발육심도화위암내부실제구조특정유료경직관적인식。위대손상구특성진행경가준학적묘술,이용FLAC3D계산재동주불동위치처관건점적응력로경,대관건점적응력상태진행분석。재UDEC태삼다변형리산적기출상증가대우절리적묘술,분석절리대손상구분포적영향,모의결과표명,절리적존재개변료수동개알후동주적응력분포,종이도치위암파손화파배구역적차이。최후,차조우과립류정서PFC대수동개알후위암적손상구진행모의,소게시출적손상국부화특정화손상구、파렬구분포특정여현장실제구유흔호적일치성。
In high stress condition,the sharp conflict between rock mass strength and stress will lead to damage to surrounding rock. Damage is the direct embodiment of the state of surrounding rock. The acoustic detection and borehole television are used to test a whole section in Jinping II deep diversion tunnel. The acoustic test results show that the section shape of low wave velocity zone is not symmetrical;and stress distribution is not completely corresponding. The borehole television was added in each acoustic drilling,a more intuitive understanding on fracture development depth and internal actual structure features of surrounding rock is obtained. In order to describe the damage zone characteristics more accurately,FLAC3D is used to calculate the stress path of the key points in different positions and analyze the stress states of the key points. Based on the discretization by UDEC voronoi polygons,adding the joint description,the influence of joint on excavation damaged zone(EDZ) is analyzed. The simulation results show that the presence of joint changes the stress distribution after excavation and leads to the difference in damage and fracture zones. With the help of particle flow code(PFC) in advantage of describing microscopic fracture characteristics,the damage zone is simulated. It is revealed the damage localization characteristics and damage zone,fracture zone distribution characteristics have the very good consistency with actual ones.