岩土力学
巖土力學
암토역학
ROCK AND SOIL MECHANICS
2014年
z1期
437-442
,共6页
圆形隧洞%均匀化方法%锚杆支护%可靠度分析
圓形隧洞%均勻化方法%錨桿支護%可靠度分析
원형수동%균균화방법%묘간지호%가고도분석
circular tunnel%homogenization method%rock bolt supporting%reliability analysis
通过采用均匀化方法,研究了圆形隧洞的锚杆支护特性,将高密度支护模式下的岩石和锚杆复合体考虑成均匀、连续、强度参数增强的等效材料,简化了岩石和锚杆间复杂的力学耦合问题。通过定义锚杆密度参数来反映不同支护模式的特性,建立锚杆密度参数与 Mohr-Coulomb 屈服准则中主要参数之间的关系,推导出等效弹性模量、等效黏聚力和等效内摩擦角的表达式,并分析比较了隧洞在支护前后的位移情况。结合可靠性理论,采用容许极限位移量作为失稳判据,分析了隧洞在支护前后的可靠性指标与破坏概率,结果表明,文中提出的方法简单可靠,锚杆支护对隧洞的位移限制效果明显,可显著提高隧洞的可靠性。
通過採用均勻化方法,研究瞭圓形隧洞的錨桿支護特性,將高密度支護模式下的巖石和錨桿複閤體攷慮成均勻、連續、彊度參數增彊的等效材料,簡化瞭巖石和錨桿間複雜的力學耦閤問題。通過定義錨桿密度參數來反映不同支護模式的特性,建立錨桿密度參數與 Mohr-Coulomb 屈服準則中主要參數之間的關繫,推導齣等效彈性模量、等效黏聚力和等效內摩抆角的錶達式,併分析比較瞭隧洞在支護前後的位移情況。結閤可靠性理論,採用容許極限位移量作為失穩判據,分析瞭隧洞在支護前後的可靠性指標與破壞概率,結果錶明,文中提齣的方法簡單可靠,錨桿支護對隧洞的位移限製效果明顯,可顯著提高隧洞的可靠性。
통과채용균균화방법,연구료원형수동적묘간지호특성,장고밀도지호모식하적암석화묘간복합체고필성균균、련속、강도삼수증강적등효재료,간화료암석화묘간간복잡적역학우합문제。통과정의묘간밀도삼수래반영불동지호모식적특성,건립묘간밀도삼수여 Mohr-Coulomb 굴복준칙중주요삼수지간적관계,추도출등효탄성모량、등효점취력화등효내마찰각적표체식,병분석비교료수동재지호전후적위이정황。결합가고성이론,채용용허겁한위이량작위실은판거,분석료수동재지호전후적가고성지표여파배개솔,결과표명,문중제출적방법간단가고,묘간지호대수동적위이한제효과명현,가현저제고수동적가고성。
A homogenization method to analyze circular tunnel with rock bolts is presented, which can simplify this kind of complex mechanical coupling problem through considering the composite material of rock mass and rock bolts as a new homogeneous, isotropic, parameters strengthened equivalent material. Rock bolt density parameter is defined to reflect the influence of high density rock bolt support pattern; Mohr-Coulomb criterion is applied to the new equivalent material; the increasement of key coefficients for Mohr-Coulomb criterion is considered to related to rock bolt density parameter; thus equivalent Young’s modulus, equivalent cohesion and equivalent friction angle for circular tunnel with rock bolts can be derived. Displacements of tunnel with and without rock bolts are compared through the existed displacement solution. Based on this solution, the reliability index and failure probability of tunnel are calculated by considering allowable ultimate displacement as instability criterion. The results show that the tunnel with rock bolts is much reliable. It is shown that the proposed method is simple and feasible and the rock bolt can improve the stability and reliability of tunnel.