高速公路砂泥岩顺层边坡组合抗滑体系协调效应研究

发布时间：2018-05-25 23:00

本文选题：正弦波 + 车辆荷载　；参考：《北京交通大学》2017年博士论文

【摘要】：长期以来,路基边坡的综合防护一直是高速公路修筑中的一个常见课题。伴随我国铁路、公路、库区或场地等工程的建设和发展,涉及了大量的路基边坡工程防护技术问题,其中以大型顺层岩石路堑高边坡防护问题为主要难点。当前对于斜交型边坡极限角度的范围尚未完善;而锚索、框架梁及抗滑桩作为治理顺层边坡的主要加固措施,虽然已广泛应用于各个领域,但是对于三者之间相互的协调作用尚缺乏系统研究。因此,本文以重庆涪(陵)丰(都)石(柱)高速公路建设项目的典型路段为例,首先采用三维数值模拟手段建立斜交边坡模型(斜交边坡模型),利用SRM法分析验证了斜交型边坡沿顺层滑移的极限角度;并基于此结果判定K27边坡的失稳机理,构建了锚框桩组合抗滑体系加固K27顺层边坡三种条件下的有限元数值模型(K27顺层边坡模型),通过分析数值模拟结果与现场监测数据对锚框桩组合抗滑体系治理K27边坡进行了系统的分析和评价。总结组合抗滑体系协调效应规律,提出动荷载作用下,锚桩内力的合理协调区间概念,提供评价动荷载边坡稳定性的另一指标以及动荷载边坡控制的新方法。主要研究内容及创新性成果如下:(1)基于斜交边坡模型模拟岩层层面与边坡坡面夹角对边坡稳定性影响,得.出斜交边坡沿顺层滑移的极限角度为30°。通过三维数值模拟计算,得出当岩层层面与边坡坡面夹角为30°时,水平位移和安全系数出现了明显的拐点,表明岩层层面与边坡坡面夹角小于30°时,岩层层面与边坡坡面夹角对稳定性影响较大,此时边坡的破坏方式主要以顺层滑移为主。即斜交边坡沿顺层滑移的极限角为30。。(2)针对大型顺层中缓倾顺层岩质高边坡,结合"边开挖边支护"的施工方式,本文在典型的滑移-拉裂式顺层破坏的基础上,提出多级拉裂式顺层滑移破坏模式。该种破坏模式在描述大型顺层中缓倾边坡的变形形态上更加贴切。(3)建立了顺层岩质边坡的数学力学模型,并基于此力学模型,构建了锚框桩组合抗滑体系加固K27边坡的三种条件下的有限元数值模型,分析了组合抗滑体系的协调效应规律,即该体系下,预应力锚索的下滑力分担值越大,抗滑桩的下滑力分担值就越小;相反的,预应力锚索的下滑力分担值越小,抗滑桩的下滑力分担值就协调大一些。通过相互的协调作用,在整个组合体系上表现出更高效的抵抗边坡下滑力的特征。(4)基于对K27滑坡形成机制的分析,在传统的滑移-拉裂顺层破坏的基础上,提出多级拉裂式顺层滑移破坏模式。这种多级别拉裂顺层滑移破坏模式在描述大型顺层中缓倾边坡的变形机制上更加贴切。并对K27滑坡推力进行了验算,自然工况下边坡的安全系数为1.07,暴雨工况下边坡的安全系数为0.94,属于不稳定边坡,需要进行抗滑治理。(5)基于对K27岩石顺层路堑高边坡的调研,综合滑坡的形成机制分析,单一的治理方法已经不能完全满足治理要求。最终建立锚框桩组合抗滑体系对K27边坡进行整治。经3D数值模拟SRM法计算,在锚框桩组合抗滑体系作用下,K27缓倾顺层路堑边坡自然工况边坡的安全系数达到了 1.74,属稳定边坡。(6)考虑坡顶正弦车载作用下,顺层边坡锚桩抗滑体系的协调机制。K27边坡坡顶改建道路的存在,是边坡抗滑设计的又一难题。通过模拟了坡顶正弦波车辆荷载作用下,边坡的自由振动分析和时程分析得出结论:坡顶动荷载作用下,锚桩组合抗滑结构各自对下滑力的承担可以相互协调;锚桩组合抗滑体系对动荷载的响应敏感度并不一致,这主要与荷载的作用位置和大小有关;提出了动荷载作用下,锚桩组合结构的合理协调区间概念。经计算,锚索的合理协调区间为[95.62,173.69];桩的合理协调区间为[197.46,286.05]。结合边坡现场的监测数据,锚索内力115.92kN以及抗滑桩内力225.64kN均在各自的合理协调区间范围内,边坡在正弦车辆荷载作用下,处于稳定状态。以此评价动荷载边坡的稳定性以及边坡动荷载控制的新方法。(7)基于锚框桩组合抗滑体系加固K27边坡暴雨入渗工况的数值模拟,得出边坡在暴雨渗流条件下最终的安全系数为1.49,治理效果良好,满足规范要求。(8)基于现场试验监测数据处理,锚索作用在边坡滑动方向上每延米的力为115.92kN/m,抗滑桩作用在边坡滑动方向上每延米的力为225.64kN/m,可知下滑力由锚索和抗滑桩共同作用承担,锚索框架梁体系承担下滑力的33.94%,抗滑桩体系承担下滑力的66.06%。均在设计值范围内,属于稳定边坡,治理效果良好。(9)基于正交试验优化设计,从治理措施的方法上分析,抗滑桩的抗滑能力大于锚索框架梁;从锚索优化设计得出,锚索的预应力以及锚固段长度对抗滑起主要作用;从抗滑桩优化设计得出,抗滑桩的桩长对抗滑起主要作用。以使K27边坡安全系数最大为标准,确定建议的优化方案。并得出建议的优化方案安全系数为1.56,不仅节约了资源的使用也满足了边坡安全系数规范要求,进而提高了资源的利用率。
[Abstract]:For a long time, the comprehensive protection of the roadbed slope has been a common problem in the construction of the highway. With the construction and development of railway, highway, reservoir area or site in China, a large number of roadbed slope engineering protection technology problems are involved, among which, the protection of high slope high slope is the main difficulty. The limit angle of oblique side slope has not been perfected, while the anchor cable, frame beam and anti slide pile are the main reinforcement measures for controlling the bedding slope, although it has been widely used in various fields, but there is no systematic research on the mutual coordination between the three. Therefore, this paper is based on the construction of the Chongqing Fu (Mausoleum) stone (capital) stone (capital) highway. The typical section of the section is taken as an example. Firstly, the oblique slope model (oblique slope model) is established by the three-dimensional numerical simulation method. The SRM method is used to verify the ultimate angle of the slanting slope along the CIS slip. Based on this result, the instability mechanism of the K27 slope is determined, and three conditions for the reinforcement of the K27 CIS slope with the anchor frame pile combination anti sliding system are constructed. Under the finite element numerical model (K27 bedding slope model), through the analysis of the numerical simulation results and the field monitoring data, the K27 slope is systematically analyzed and evaluated. The coordination effect law of the combined anti sliding system is summarized, and the rational coordination interval concept of the internal force of the anchor pile under the action of dynamic load is put forward, and the evaluation is provided. Another index of the stability of the dynamic load slope and the new method of controlling the dynamic load slope. The main research content and the innovative results are as follows: (1) the influence of the angle between the rock layer and the slope of the slope on the stability of the slope is simulated on the basis of the slope intersection slope model, and the ultimate angle of the slip slope along the CIS layer is 30 degrees. The calculation shows that when the angle between the rock layer and the slope is 30 degrees, the horizontal displacement and the safety factor have obvious inflection point. It shows that the angle between the rock layer and the slope slope is less than 30 degrees, the angle between the rock layer and the slope slope has great influence on the stability, and the slope failure mode is mainly based on the CIS layer slip. The limit angle of layer slip is 30.. (2) in view of the slow dip and bedding high rock slope in the large CIS layer, combined with the construction method of "side excavation and side support", on the basis of typical slip and crack type failure, the multistage sliding failure mode is put forward. This type of failure mode is used to describe the deformation form of the gently inclined slope in the large CIS layer. (3) the mathematical mechanics model of the bedding rock slope is established, and based on this mechanical model, the finite element numerical model is constructed under three conditions of the anchor frame pile combination anti sliding system to reinforce the K27 slope, and the coordination effect law of the combined anti sliding system is analyzed. The lower the sharing value of the slide force of the pile is smaller; on the contrary, the smaller the sharing value of the slide force of the prestressed anchor cable is, the greater the sharing value of the slide force of the anti slide pile is coordinated. Through the coordination of each other, the characteristic of resisting the slope sliding force is more efficient in the whole system. (4) based on the analysis of the formation mechanism of the landslide, the traditional slippage is carried out on the basis of the analysis of the formation mechanism of the landslide. On the basis of the failure of the shift and pull crack, the multilevel split type slip failure mode is proposed. This multi level sliding failure mode is more suitable for describing the deformation mechanism of the gently inclined slope in the large CIS layer. The K27 landslide thrust is checked. The safety factor of the slope is 1.07 under the natural condition, and the slope under the heavy rain condition. The safety factor is 0.94, which belongs to the unstable slope and needs anti sliding treatment. (5) based on the investigation of the high slope of the K27 rock CIS cutting and the analysis of the formation mechanism of the landslide, the single treatment method can not fully meet the requirements of the treatment. Finally, the anti sliding system of the anchor frame pile combination is established to the K27 slope through the 3D numerical simulation method. Calculation, under the action of anchor frame pile combination anti sliding system, the safety factor of the slope of K27 gently inclined bedding slope is 1.74, it is a stable slope. (6) under the sinusoidal loading of the slope, the coordination mechanism of the anti sliding system of the anchor pile of the bedding slope, the existence of the rebuilt Road on the slope top of the slope, is another difficult problem of the slope anti sliding design. The free vibration analysis and time history analysis of the slope under the action of the sinusoidal load on the top of the slope have been simulated. The conclusion is that under the action of the dynamic load of the slope, the anti sliding structure of the anchor pile can be coordinated with each other, and the response sensitivity of the anchor pile combination anti sliding system to the dynamic load is not consistent, which is mainly with the position of the load. The reasonable coordination interval concept of anchor pile composite structure under dynamic load is put forward. The reasonable coordination interval of the anchor cable is [95.62173.69]. The reasonable coordination interval of the pile is [197.46286.05]. combined with the monitoring data of the slope site, and the internal force 115.92kN of the anchorage cable and the internal force of the anti slide pile are in their respective reasonable coordination. In the interval range, the slope is in a stable state under the load of sinusoidal vehicle. In order to evaluate the stability of the dynamic load slope and the new method of controlling the dynamic load of the slope. (7) based on the numerical simulation of the infiltration condition of the K27 slope strengthened by the anchor frame pile combination anti sliding system, the final safety factor of the side slope under the condition of the torrential rain is 1.4. 9, the effect of the control is good. (8) based on the field test monitoring data processing, the force of the anchor cable Acting on the slope sliding direction is 115.92kN/m, and the force of the anti slide pile acting on the slide direction of the slope is 225.64kN/m. The slide force is assumed by the joint action of the anchor cable and the anti slide pile, and the anchor cable frame beam system bears the assumption. 33.94% of the sliding force, the 66.06%. of the anti slide pile system undertakes the sliding force in the design value range, it belongs to the stable slope, and the effect is good. (9) based on the orthogonal test optimization design, the anti slide pile's anti slide ability is larger than the anchor frame beam from the method of the control measures. The anchor cable prestress and the length of anchor length are obtained from the anchor cable optimization design. From the optimum design of the anti slide pile, the main effect of the pile length of anti slide pile is obtained. To make the maximum safety factor of the K27 slope as the standard, the proposed optimization scheme is determined. The proposed optimization scheme is 1.56, which not only saves the use of resources but also satisfies the standard requirements of the slope safety factor. And the utilization of resources has been improved.
【学位授予单位】：北京交通大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：U416.14

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