岩土力学
巖土力學
암토역학
ROCK AND SOIL MECHANICS
2014年
1期
217-225
,共9页
框架锚杆%系统可靠性%Winkler弹性地基梁%侧压力系数%相关系数
框架錨桿%繫統可靠性%Winkler彈性地基樑%側壓力繫數%相關繫數
광가묘간%계통가고성%Winkler탄성지기량%측압력계수%상관계수
frame anchor%system reliability%Winkler elastic foundation beam%lateral pressure coefficient%correlation coefficient
将框架梁在张拉阶段或工作阶段时纵梁与横梁的破坏、梁的正截面与斜截面的破坏以及锚杆的破坏等主要失效模式视为串联系统，提出了框架预应力锚索的分阶段系统可靠性计算模型。在张拉阶段，将锚索力按照位移协调和静力平衡的原则分配在纵、横梁上，然后按Winkler弹性地基梁模型分别计算单片梁的内力；在工作阶段，将侧向土压力系数视为随机变量，框架梁视为土压力作用下的简支梁来计算其内力。基于各失效模式功能函数之间的相关系数矩阵，导出了预应力锚索框架的系统可靠性计算方法并编制了计算程序。对某工程实例的计算结果表明，预应力锚索框架的失效概率主要由纵梁在工作阶段和张拉阶段的正截面失效概率及锚杆的失效概率三者共同决定，而假设此3种失效模式相互独立的系统失效概率与考虑失效模式相关性的系统失效概率误差为8.1%。
將框架樑在張拉階段或工作階段時縱樑與橫樑的破壞、樑的正截麵與斜截麵的破壞以及錨桿的破壞等主要失效模式視為串聯繫統，提齣瞭框架預應力錨索的分階段繫統可靠性計算模型。在張拉階段，將錨索力按照位移協調和靜力平衡的原則分配在縱、橫樑上，然後按Winkler彈性地基樑模型分彆計算單片樑的內力；在工作階段，將側嚮土壓力繫數視為隨機變量，框架樑視為土壓力作用下的簡支樑來計算其內力。基于各失效模式功能函數之間的相關繫數矩陣，導齣瞭預應力錨索框架的繫統可靠性計算方法併編製瞭計算程序。對某工程實例的計算結果錶明，預應力錨索框架的失效概率主要由縱樑在工作階段和張拉階段的正截麵失效概率及錨桿的失效概率三者共同決定，而假設此3種失效模式相互獨立的繫統失效概率與攷慮失效模式相關性的繫統失效概率誤差為8.1%。
장광가량재장랍계단혹공작계단시종량여횡량적파배、량적정절면여사절면적파배이급묘간적파배등주요실효모식시위천련계통，제출료광가예응력묘색적분계단계통가고성계산모형。재장랍계단，장묘색력안조위이협조화정력평형적원칙분배재종、횡량상，연후안Winkler탄성지기량모형분별계산단편량적내력；재공작계단，장측향토압력계수시위수궤변량，광가량시위토압력작용하적간지량래계산기내력。기우각실효모식공능함수지간적상관계수구진，도출료예응력묘색광가적계통가고성계산방법병편제료계산정서。대모공정실례적계산결과표명，예응력묘색광가적실효개솔주요유종량재공작계단화장랍계단적정절면실효개솔급묘간적실효개솔삼자공동결정，이가설차3충실효모식상호독립적계통실효개솔여고필실효모식상관성적계통실효개솔오차위8.1%。
The frame prestressed anchor cable computational model for system reliability is put forward basing on a series system, which is constituted with main failure modes of the frame beam destruction in tension stage or in working stage, destruction of stringers and beams, destruction of the beam in cross-section and oblique section, and anchor damage. During tensioning stage, the anchor cable force is assigned on the beams in accordance with the principles of displacement coordination and static balance;internal forces of the monolithic beam is calculated respectively by Winkler elastic foundation beam model. In the working stage, to calculate their internal forces, the lateral earth pressure coefficient is regarded as random variables, frame beams as simply supported beam under the earth pressure. Basing on the correlation coefficient matrix of the failure mode function, prestressed anchor computational model for reliability of the system and computer program are then derived. The results of an engineering example show that the probability of failure of the prestressed anchor frame is determined by three factors:cross-section failure probability of in working stage, cross-section failure probability of tensioned stage and anchor bolt failure probability. Assuming the error of three failure modes interdependent system failure probability and system failure probability considering correlation is 8.1%.
