高路堤预应力锚索桩板墙承载特性分析

发布时间：2018-01-16 12:07

本文关键词：高路堤预应力锚索桩板墙承载特性分析　出处：《岩土工程学报》2015年10期 　论文类型：期刊论文

【摘要】：以昆明—曼谷国际公路k70路堤加固工程为背景,采用原位测试方法,完成了不同工况下预应力锚索桩板墙承载特性的现场试验。通过观测结构位移、土压力、桩身内力以及锚索预应力等,系统分析了预应力锚索桩板墙的受力特性与力学行为。锚索桩板墙对高路堤的加固效果显著,填筑初期结构位移随填土高度线性增加,锚索施工后增速有所减缓;初始填筑阶段,抗滑桩变形以刚性倾斜为主,随着锚索张拉和桩后填土不断增高桩身产生了较为明显的弯曲变形。作用在抗滑桩后的土压力大致呈三角形分布,板后土压力大致呈抛物线型分布;相同埋深条件下作用在抗滑桩上的土压力明显大于挡板,原因在于相邻抗滑桩间产生了明显的土拱效应,下部相邻抗滑桩间的土拱效应更强;与解析解的对比结果表明,实测最大桩后土压力与滑坡推力接近,远小于被动土压力;实测板后土压力与主动土压力接近,工程设计中可选取Rankine主动土压力作为挡板的设计荷载,在不利位置采取增大板厚等措施避免挡板发生破坏。采用弹性弯曲梁理论对锚索桩板墙内力计算的结果与实测结果基本一致。张拉锁定初期锚索预应力损失较大,约为设计荷载的10%,后期锚索预应力逐渐趋于稳定,锚索预应力长期损失约为设计荷载值的12%~15%。
[Abstract]:Taking the K70 embankment reinforcement project of Kunming Bangkok International Highway as the background, the in-situ test method was used to complete the field test of the bearing characteristics of prestressed anchor cable pile-slab wall under different working conditions. The displacement of the structure was observed. Soil pressure, internal force of pile body and prestressing force of anchor cable are analyzed systematically. The mechanical behavior of prestressed cable pile and slab wall is analyzed systematically. The reinforcement effect of anchor cable pile and plate wall on high embankment is remarkable. The initial structural displacement increases linearly with the filling height, and the growth rate slows down after the construction of anchor cable. In the initial filling stage, the deformation of anti-slide pile is mainly rigid inclined, and with the continuous increase of anchor cable tension and pile backfill, the pile body produces more obvious bending deformation, and the earth pressure acting on the anti-slide pile is roughly triangular distribution. The earth pressure behind the plate is approximately parabolic; The earth pressure acting on the anti-slide pile under the same buried depth is obviously larger than that on the baffle, the reason is that the soil arch effect is obvious between adjacent anti-slide piles, and the soil arch effect between the adjacent anti-slide piles in the lower part is stronger. The results of comparison with the analytical solution show that the measured maximum earth pressure behind the pile is close to the landslide thrust and is much smaller than the passive earth pressure. The measured earth pressure behind the plate is close to the active earth pressure. In the engineering design, the active earth pressure of Rankine can be selected as the design load of the baffle. Measures such as increasing plate thickness in unfavorable position are taken to avoid the damage of baffle. The calculation results of internal force of anchor cable pile, plate wall by using elastic bending beam theory are in good agreement with the measured results. The prestressing loss of anchor cable in the early stage of tension locking is larger. . About 10 of the design load, the anchoring cable prestress tends to stabilize gradually in the late stage, the long-term loss of the anchor cable prestress is about 12 / 15 of the design load value.
【作者单位】：中国矿业大学(北京)资源与安全工程学院;中铁西北科学研究院有限公司;
【基金】：国家自然科学基金项目(51574245,41002090)
【分类号】：U416.1
【正文快照】： 0引言预应力锚索桩板墙是一种新型路堤支挡结构,由抗滑桩、挡板和预应力锚索组成(图1)。20世纪90年代,中国南(宁)—昆(明)铁路首次应用预应力锚索桩板墙并取得了成功[1]。由于该结构承载力高、组合灵活并且适用性强,近年来,在中国西南和华南山区高路堤加固中得到了广泛应用[2-

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