岩土力学
巖土力學
암토역학
ROCK AND SOIL MECHANICS
2013年
8期
2271-2279
,共9页
江权%陈建林%冯夏庭%陈静%崔洁%万祥兵%侯靖
江權%陳建林%馮夏庭%陳靜%崔潔%萬祥兵%侯靖
강권%진건림%풍하정%진정%최길%만상병%후정
大型地下洞室%对穿预应力锚索%锚索失效%锚索-围岩耦合元件模型
大型地下洞室%對穿預應力錨索%錨索失效%錨索-圍巖耦閤元件模型
대형지하동실%대천예응력묘색%묘색실효%묘색-위암우합원건모형
large underground cavern%prestressed thru-anchor cable%failure of anchor cable%interactive model of cable and rock
以锦屏二级水电站地下厂房与主变室之间中隔墙的多根对穿预应力锚索失效实例为背景,首先总结对穿预应力锚索失效的多种现场表现形式,采用现场取证和室内试验再现的方式论证锚索钢绞线断裂的拉破坏模式。将对穿锚索视为弹脆性体,被锚固围岩视为黏弹性体,提出描述对穿预应力锚索与被锚固围岩之间相互作用关系的锚索-围岩耦合元件模型,并据此分别阐明在洞室开挖卸荷阶段和围岩时效变形阶段中预应力锚索的力学响应机制和荷载变化规律。最后,在现场调研、室内试验和机制分析基础上,综合分析导致锦屏二级水电站地下厂房与主变室之间对穿锚索失效的主要原因,并探讨对穿预应力锚索与被锚固围岩之间对立统一的矛盾关系以及大型洞室群预应力锚索支护时机问题。
以錦屏二級水電站地下廠房與主變室之間中隔牆的多根對穿預應力錨索失效實例為揹景,首先總結對穿預應力錨索失效的多種現場錶現形式,採用現場取證和室內試驗再現的方式論證錨索鋼絞線斷裂的拉破壞模式。將對穿錨索視為彈脆性體,被錨固圍巖視為黏彈性體,提齣描述對穿預應力錨索與被錨固圍巖之間相互作用關繫的錨索-圍巖耦閤元件模型,併據此分彆闡明在洞室開挖卸荷階段和圍巖時效變形階段中預應力錨索的力學響應機製和荷載變化規律。最後,在現場調研、室內試驗和機製分析基礎上,綜閤分析導緻錦屏二級水電站地下廠房與主變室之間對穿錨索失效的主要原因,併探討對穿預應力錨索與被錨固圍巖之間對立統一的矛盾關繫以及大型洞室群預應力錨索支護時機問題。
이금병이급수전참지하엄방여주변실지간중격장적다근대천예응력묘색실효실례위배경,수선총결대천예응력묘색실효적다충현장표현형식,채용현장취증화실내시험재현적방식론증묘색강교선단렬적랍파배모식。장대천묘색시위탄취성체,피묘고위암시위점탄성체,제출묘술대천예응력묘색여피묘고위암지간상호작용관계적묘색-위암우합원건모형,병거차분별천명재동실개알사하계단화위암시효변형계단중예응력묘색적역학향응궤제화하재변화규률。최후,재현장조연、실내시험화궤제분석기출상,종합분석도치금병이급수전참지하엄방여주변실지간대천묘색실효적주요원인,병탐토대천예응력묘색여피묘고위암지간대립통일적모순관계이급대형동실군예응력묘색지호시궤문제。
This paper pays main attention on the failure performance and excavation induced interaction of prestressed thru-anchor cable by a case study. In-situ investigation had shown that there were several failure formats of prestressed thru-cable in the Jinping II underground powerhouse. The observed proof also indicated that this kind of break of thru-cables belongs to tensile failure due to unloading deformation and time-dependent rheology of underground caverns. Thus, a new cell model is purposed to describe the interactive relation between thru-anchor cables and reinforced rock. This cable-rock cell model has special structure, i.e. an elasto-brittle cell is employed to representing the mechanical behavior of thru-anchor cables, and a viscoelastic Kelvin-Hooke cell is employed to representing the mechanical response of host rock. Based on this coupled model, several mechanical parameters which influence the cable’s load are discussed, including elastic modulus of cable, elastic modulus of rock, viscoelastic modulus of rock and coefficient of rock viscosity, etc. This discussion can help us to recognize the ambivalent relationship between thru-anchor cable and reinforced surrounding rock.