岩土力学
巖土力學
암토역학
ROCK AND SOIL MECHANICS
2015年
2期
600-606
,共7页
地震%裂隙%边坡稳定
地震%裂隙%邊坡穩定
지진%렬극%변파은정
earthquake%crack%slope stability
在地震作用下岩质边坡内部裂隙可能开裂扩展,对边坡稳定造成不利影响。利用扩展有限元法模拟岩质边坡内部裂隙在地震作用下的开裂扩展,根据扩展后的裂隙分析边坡潜在滑面,采用矢量和法计算边坡在震前、地震过程及震后的安全系数。结果表明:在汶川地震波作用下LLT1与LLT2裂隙均开裂扩展,开裂方向与水平方向夹角近45°,其中LLT1裂隙顶部开裂至边坡面。震前安全系数为1.75,地震过程中最小安全系数为1.01,震后安全系数为1.05。说明了即便是边坡在震前稳定性较好,但由于地震作用使得裂隙扩展贯通至边坡表面,导致滑体抗滑力降低,边坡震后稳定性显著降低。虽然地震过程中边坡并未失稳破坏,若在震后受到其他外部作用则可能失稳破坏,引发次生灾害。
在地震作用下巖質邊坡內部裂隙可能開裂擴展,對邊坡穩定造成不利影響。利用擴展有限元法模擬巖質邊坡內部裂隙在地震作用下的開裂擴展,根據擴展後的裂隙分析邊坡潛在滑麵,採用矢量和法計算邊坡在震前、地震過程及震後的安全繫數。結果錶明:在汶川地震波作用下LLT1與LLT2裂隙均開裂擴展,開裂方嚮與水平方嚮夾角近45°,其中LLT1裂隙頂部開裂至邊坡麵。震前安全繫數為1.75,地震過程中最小安全繫數為1.01,震後安全繫數為1.05。說明瞭即便是邊坡在震前穩定性較好,但由于地震作用使得裂隙擴展貫通至邊坡錶麵,導緻滑體抗滑力降低,邊坡震後穩定性顯著降低。雖然地震過程中邊坡併未失穩破壞,若在震後受到其他外部作用則可能失穩破壞,引髮次生災害。
재지진작용하암질변파내부렬극가능개렬확전,대변파은정조성불리영향。이용확전유한원법모의암질변파내부렬극재지진작용하적개렬확전,근거확전후적렬극분석변파잠재활면,채용시량화법계산변파재진전、지진과정급진후적안전계수。결과표명:재문천지진파작용하LLT1여LLT2렬극균개렬확전,개렬방향여수평방향협각근45°,기중LLT1렬극정부개렬지변파면。진전안전계수위1.75,지진과정중최소안전계수위1.01,진후안전계수위1.05。설명료즉편시변파재진전은정성교호,단유우지진작용사득렬극확전관통지변파표면,도치활체항활력강저,변파진후은정성현저강저。수연지진과정중변파병미실은파배,약재진후수도기타외부작용칙가능실은파배,인발차생재해。
Internal crack in rock slope may grow under seismic loading, which would have an adverse effect on slope stability. By taking advantage of extended finite element method (XFEM), the development of cracks in a rock slope located in the southwest China under seismic loading is simulated. An analysis of the potential sliding surface is carried out according to the crack after extension, and the factors of safety are calculated with vector sum analysis method (VSAM) before, during and after earthquake. The result shows, under the loading of Wenchuan seismic waves, both crack LLT1 and crack LLT2 grow. The angle between growth-direction and the horizontal is nearly 45 degree, and the crack LLT1 grows to the slope surface. The factors of safety before and after earthquake are 1.75 and 1.05 respectively, and the minimum factor of safety during the earthquake is 1.01. This illustrates that the slope is stable before earthquake, but the anti-sliding force and the slope stability are both reduced because of the growth of crack under the seismic loading. Even if the slope is stable in the process of the earthquake, it may collapse subjected to other forces after earthquake.