黄土高边坡土钉-预加固桩复合支护体系性状分析

发布时间：2018-05-28 23:02

本文选题：黄土高边坡 + 土钉-预加固桩　；参考：《岩土力学》2014年07期

【摘要】：土钉-预加固桩复合支护技术已在基坑及边坡工程中取得了大量应用,但在黄土高边坡开挖中的应用相对较少。基于详细的现场监测数据并辅以有限元数值计算,分析了边坡开挖过程中支护体系受力及变形随时间和空间的变化规律。结果表明:预加固桩的水平位移随着时间的推移与开挖深度的增加呈增大趋势,并最终趋于稳定,同时,桩身剪力及弯矩亦随开挖的进行而不断增大;剪力最大值的位置不断下移,说明边坡的潜在滑动面有不断向下扩展的趋势。与深基坑支护桩的土压力分布相比,土钉-预加固桩复合支护体系中桩后土压力随开挖呈不断减小的趋势,但桩前土压力随着开挖深度的增加,有增有减。随着施工开挖深度的增加,土钉所测得的应力有着明显的增大,说明土钉对抑制坡体变形起到了一定作用。在预加固桩的影响下,桩上方坡体的最危险破裂面为圆弧状,其剪出口位于预加固桩桩顶处。开挖深度较浅时,土钉对整体稳定性的贡献较大,而随着开挖深度的变大,预加固桩的加固效果开始占主导地位。
[Abstract]:Soil nailing and prestrengthening pile composite support technology has been widely used in foundation pit and slope engineering, but it is less applied in loess high slope excavation. Based on the detailed field monitoring data and finite element numerical calculation, the law of stress and deformation of support system with time and space during slope excavation is analyzed. The results show that the horizontal displacement of pre-strengthened pile increases with time and the depth of excavation increases, and finally tends to be stable, at the same time, the shear force and bending moment of pile body increase with the excavation. The position of the maximum shear force is moving downward, which indicates that the potential sliding surface of the slope tends to expand downward. Compared with the soil pressure distribution of the deep foundation pit retaining pile, the soil pressure after the pile is decreasing with excavation in the composite support system of soil nailing and prestrengthening pile, but the soil pressure in front of pile increases and decreases with the increase of excavation depth. With the increase of excavation depth, the stress measured by soil nailing is obviously increased, which indicates that soil nailing plays a certain role in restraining deformation of slope body. Under the influence of pre-strengthened pile, the most dangerous fracture surface of the slope above the pile is arc, and the shear outlet is located at the top of pre-strengthened pile. When the excavation depth is shallow, the soil nailing makes a great contribution to the overall stability, but with the excavation depth increasing, the reinforcement effect of pre-strengthened pile begins to dominate.
【作者单位】：西南交通大学地质工程系;中铁第四勘察设计院集团有限公司;
【基金】：国家自然科学基金项目(No.41172260,No.41372292,No.51108393) 高等学校博士学科点专项科研基金(No.20110184110018) 国家重点基础研究发展计划(973计划)(No.2008CB425801) 教育部创新团队资助(No.IRT13092) 西南交通大学2014年博士生创新基金
【分类号】：TU472

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