土木建筑与环境工程
土木建築與環境工程
토목건축여배경공정
Journal of Chongqing Jianzhu University
2015年
4期
67-76
,共10页
边坡稳定可靠性%强度参数%统计特性%区间性%空间变化性
邊坡穩定可靠性%彊度參數%統計特性%區間性%空間變化性
변파은정가고성%강도삼수%통계특성%구간성%공간변화성
slope stability reliability%strength parameters%statistical property%interval%spatial variability
由于对边坡强度参数统计特性考虑不全面,使得边坡可靠性指标计算值偏小,对应的失效概率偏大,常常超过10%,设计中难以采纳,造成地基可靠度规范的制定和执行进展缓慢。以某高速公路全风化花岗岩土质高边坡为工程背景,在分析土质参数统计特性的基础上,采用极限平衡理论和蒙特卡罗模拟法,系统地分析了土质强度参数的均值不定性、变异性、相关性、区间特性和空间变化性等对边坡稳定可靠性的影响。结果表明:土性参数的各种统计特性对边坡稳定可靠性均具有不同程度的影响。可靠性指标计算值随抽样距离的减小而增加,随 c 或φ均值的增大而增加,随c 和φ的变异系数的增大而减小,随 c 和φ相关系数绝对值的增大而增加,考虑区间性后可靠性指标计算值也明显变大。即变异性对边坡稳定不利,而相关性、区间性和空间变化性对边坡稳定有利。因此,准确而全面地考虑土质参数的统计特性,尤其是在参数变异性和相关性的基础上加以考虑土性参数空间变化性和区间性会更加符合工程实际,且计算结果趋于安全,有利于地基可靠度规范的推广运用和边坡工程的安全评价。
由于對邊坡彊度參數統計特性攷慮不全麵,使得邊坡可靠性指標計算值偏小,對應的失效概率偏大,常常超過10%,設計中難以採納,造成地基可靠度規範的製定和執行進展緩慢。以某高速公路全風化花崗巖土質高邊坡為工程揹景,在分析土質參數統計特性的基礎上,採用極限平衡理論和矇特卡囉模擬法,繫統地分析瞭土質彊度參數的均值不定性、變異性、相關性、區間特性和空間變化性等對邊坡穩定可靠性的影響。結果錶明:土性參數的各種統計特性對邊坡穩定可靠性均具有不同程度的影響。可靠性指標計算值隨抽樣距離的減小而增加,隨 c 或φ均值的增大而增加,隨c 和φ的變異繫數的增大而減小,隨 c 和φ相關繫數絕對值的增大而增加,攷慮區間性後可靠性指標計算值也明顯變大。即變異性對邊坡穩定不利,而相關性、區間性和空間變化性對邊坡穩定有利。因此,準確而全麵地攷慮土質參數的統計特性,尤其是在參數變異性和相關性的基礎上加以攷慮土性參數空間變化性和區間性會更加符閤工程實際,且計算結果趨于安全,有利于地基可靠度規範的推廣運用和邊坡工程的安全評價。
유우대변파강도삼수통계특성고필불전면,사득변파가고성지표계산치편소,대응적실효개솔편대,상상초과10%,설계중난이채납,조성지기가고도규범적제정화집행진전완만。이모고속공로전풍화화강암토질고변파위공정배경,재분석토질삼수통계특성적기출상,채용겁한평형이론화몽특잡라모의법,계통지분석료토질강도삼수적균치불정성、변이성、상관성、구간특성화공간변화성등대변파은정가고성적영향。결과표명:토성삼수적각충통계특성대변파은정가고성균구유불동정도적영향。가고성지표계산치수추양거리적감소이증가,수 c 혹φ균치적증대이증가,수c 화φ적변이계수적증대이감소,수 c 화φ상관계수절대치적증대이증가,고필구간성후가고성지표계산치야명현변대。즉변이성대변파은정불리,이상관성、구간성화공간변화성대변파은정유리。인차,준학이전면지고필토질삼수적통계특성,우기시재삼수변이성화상관성적기출상가이고필토성삼수공간변화성화구간성회경가부합공정실제,차계산결과추우안전,유리우지기가고도규범적추엄운용화변파공정적안전평개。
Without comprehensive consideration of the strength parameters statistical properties,the slope reliability index calculation value become smaller and the failure probability become larger,often more than 10%,which was difficult to adopt in design.Hence,the foundation reliability norm’s formulate and implement made slow progress. Take a completely weathered granite soil slope of an expressway as engineering background,and based on the analysis of the statistical characteristics of soil parameters,the limit equilibrium theory and monte carlo simulation method were used to systematically analyze the soil strength parameters’mean uncertainty,variability,correlation and interval characteristics and spatial variability of impact on the reliability of the slope stability.The results showed that all kinds of statistical features of soil parameters had varying degrees impact on slope stability reliability.The reliability index calculation value increased with the decrease of the sampling distance,increased with the increase of the mean values of c or φ,decreased with the increase of the variation coefficientc and φ, increased with the increase of the correlation coefficient absolute value of c and φ,and the reliability index calculation value became obvious bigger when interval characteristics were considered.The findings indicated that variability was adverse to the slope stability and the correlation,interval characteristics and spatial variability were good for the slope stability.Therefore,with accurate and comprehensive consideration of the soil parameters statistical features,especially with the consideration of space variability and interval characteristics on the basis of the consideration of parameters variability and correlation will be more in line with the engineering practice,and the calculation results tend to be more reliable.It is advantageous to the adopt reliability norm and safety evaluation of slope engineering.