黄土边坡开挖与支护效应的离心模拟试验研究

黄土边坡在开挖卸载过程中的稳定性分析及其防护在边坡工程中占有重要地位。采用西南交通大学土工离心机进行了1组非支护边坡和2组土钉支护边坡的离心模型试验,研究了开挖卸载过程中黄土边坡的变形特性、稳定性变化规律及土钉的加固效应。离心模型试验研究表明,土钉能够显著提高黄土边坡的稳定性。土钉支护的边坡土体,因土钉的锚固效应,边坡的变形范围更大,但变形量较小,最大变形量并不在坡面,而是发生在坡面下的锚固区域内,非支护黄土边坡的潜在滑移面产生于距坡顶约40cm处,土钉支护后,黄土边坡基本不会发生破坏。对于抵抗边坡发生变形而言,不等长土钉支护的效果要优于等长土钉支护,研究成果为黄土边坡的开挖与防护提供了参考。

Centrifuge model tests on excavation and reinforcement effect of loess slope

The stability analysis and its protection in the excavation and unloading course of loess slope occupy an important position in the slope engineering. One centrifugal model test of non-reinforcement slope and two centrifugal model tests of soil nailing reinforcement slopes are performed on the centrifuge at Southwest Jiaotong University. The deformation characteristics, reinforcement effect of soil nailing and the stability in the excavation and unloading course of loess slopes are studied. Results of centrifuge model tests show that soil nailing can greatly increase the stability of loess slopes. Due to the anchoring effect of soil nailing, the range of deformation is wider, but magnitude is smaller, and the largest deformation is not in the surface, but in the anchor region of the nailed slope. Non-reinforcement loess slope has the potential failure surface of about 40cm below its crest. The models were substantially stable against failure and deformation due to soil nailing. The reinforcement with unequal length of soil nails is superior to that of equal length of soil nails for the resistance to slope failure. The research results provide references for excavation and reinforcement of loess slopes.