小盘岭岩质高边坡施工过程监测及稳定性分析

发布时间：2018-11-06 14:39

【摘要】：目前我国正处在经济建设高速发展的时期,随着国民经济的发展,公路等级越来越高,高填深挖已经不可避免,复杂地形条件下修建高等级公路的情况日益增多,复杂的岩质高边坡日益增多。由于岩质高边坡在施工中容易失稳,不仅造成大量的经济损失,甚至造成一定的人员伤亡；因此,进行岩质高边坡施工过程监测及稳定性分析研究有非常重要的现实意义。本文以辽宁省建兴高速公路小盘岭岩质高边坡为工程背景,首先归纳了岩质边坡的破坏类型、影响稳定的因素及不同岩坡变形破坏的不同模式,找出影响小盘岭边坡稳定性的主要因素；然后采用数值模拟和现场监测相结合的方法进行研究。采用数字摄影测量技术对边坡的结构面信息进行采集、分析和归类,然后把结构面信息运用到离散元软件3DEC中,数值模拟边坡施工过程并进行稳定性分析和变形预测；再用全站仪和水准仪对边坡施工过程进行变形监测并与预测情况进行对比；验证数值模拟预测与现场实际的符合状况后,对下一级边坡的开挖情况进行预测,并研究不同支护方案对边坡稳定性的影响,从而优化边坡的支护设计方案。研究表明,第三级边坡开挖后坡体开挖面Z方向0-15m区域开始有剪切塑性区出现,但仍保持整体稳定：第二级边坡开挖时位移矢量、速度矢量大量集中在坡体开挖面Z方向0-15m区域的节理上,并呈矢量逐渐增加趋势,边坡出现了局部失稳破坏；第一级边坡开挖过程中,边坡大部分区域都发生明显位移,且位移矢量、速度矢量继续增大,此时边坡发生整体失稳破坏。针对该边坡情况,提出了监测点的优化布设方案,边坡沿线方向0-15m区域重点监测,16-50m区域减少监测点,经优化,监测点个数由20个减为12个;并且经过数值模拟不同设计方案的边坡状况,确定了第四级边坡支护设计改为无需添加锚杆,第三级边坡在沿线方向0-15m区域加长锚杆长度,由8m改为12m,沿线方向16-50m区域横向放宽锚杆支护间距,由2m改为5m；从而达到了保证工程安全、降低施工难度、保证工程措施经济合理的目的。
[Abstract]:At present, our country is in the period of rapid development of economic construction. With the development of national economy, highway grade is getting higher and higher, high fill and deep excavation is inevitable, and the situation of building high grade highway under complex terrain condition is increasing day by day. Complex high rock slope is increasing day by day. Because rock high slope is easy to lose stability in construction, it not only causes a lot of economic losses, but also causes certain casualties, so it is of great practical significance to monitor the construction process and analyze the stability of rock high slope. Taking the Xiaopanling high rock slope of Jianxing Expressway in Liaoning Province as the engineering background, the failure types of rock slope, the factors affecting stability and the different modes of deformation and failure of different rock slopes are first summarized in this paper. Find out the main factors that affect the stability of Xiaopanling slope; Then the method of numerical simulation and field monitoring is used to study. Digital photogrammetry is used to collect, analyze and classify the structural surface information of slope. Then the information of structural plane is applied to discrete element software 3DEC to simulate the construction process of slope and to analyze the stability and predict the deformation. Then the deformation of the slope construction process is monitored with total station and level and compared with the prediction. After verifying that the numerical simulation prediction is in accordance with the actual situation on the spot, the excavation condition of the next grade slope is predicted, and the influence of different supporting schemes on the slope stability is studied, so as to optimize the slope support design scheme. The results show that the shear plastic zone appears in the Z direction of the excavation surface of the slope after the third stage slope excavation, but it is still stable, and the displacement vector of the second stage slope is obtained when the slope is excavated. The velocity vector is concentrated on the joint of Z direction 0-15m area of the slope body excavating surface, and the velocity vector increases gradually, and the slope appears local instability failure. During the excavation of the first stage slope, the displacement and velocity vectors continue to increase in most areas of the slope, and the overall instability of the slope occurs. According to the condition of the slope, the optimal layout scheme of monitoring points is put forward. The monitoring points are reduced from 20 to 12 in the direction of 0-15m along the slope, and the number of monitoring points is reduced from 20 to 12 in the 16-50m area. Through numerical simulation of the slope conditions of different design schemes, it is determined that the design of the fourth grade slope support needs no additional bolt, and the third stage slope lengthens the length of the anchor rod from 8 m to 12 m in the direction of 0-15 m along the line. Along the direction of 16-50m area lateral relaxation of bolting support distance from 2m to 5m; In order to ensure the safety of the project, reduce the difficulty of construction, ensure the economic and reasonable engineering measures.
【学位授予单位】：东北大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU753

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