新元洁能电厂土质（回填）高边坡锚索预应力损失研究

发布时间：2018-03-17 07:04

本文选题：土质高边坡　切入点：土质回填高边坡　出处：《西安科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：我国人口众多,为了有效利用土地资源及矿物资源,在山地进行城市建设、修建铁路、公路及水利设施、建设大型厂矿等活动,往往通过高填深挖平整土地,这样就形成了大量的土质挖方和回填高边坡。在外界条件的影响下极易发生边坡失稳,从而威胁到建设工程及人民的生命财产安全。预应力锚索是广泛使用于边(滑)坡的防护措施,而土层中的预应力锚索的预应力损失是非常大的,所以在土质(回填)高边坡中预应力锚索长期稳定直接关系到被防护边坡的安全性和永久性。通过收集资料对土质高边坡中预应力锚索加固机理进行了分析,再以新元洁能电厂其中一个土质高边坡和一个土质回填高边坡防护工程为研究对象,通过对施工过程和施工后的监测,结合现场土工试验分析,研究得出:(1)影响锚索预应力损失的主要因素为岩土体蠕变、张拉锁定损失、钢绞线松弛和外部条件影响,其中土质高边坡的岩土体蠕变对锚索预应力的影响比岩质边坡的大;(2)得出土质高边坡中锚索预应力损失的一般规律,但土质回填高边坡的锚索预应力损失较小,存在这一差异的原因是回填土的压缩性低、无湿陷性即其受荷载的长期作用的变形量小于前者;(3)超张拉和补张拉都能使锚索预应力达到设计要求,作为施工方超张拉更为经济适用。注浆可以改善土质高边坡的力学性质,对于土层松软,裂隙发育的边坡,锚固技术与注浆措施配合适用,能缓解锚索与应力损失的同时提高坡体的稳定性。对于土质回填高边坡,回填土的压实度达到90%以上对于锚索质量和工程建设是有利和保障的。通过以上对土质高边坡(特别是土质回填高边坡)锚索预应力损失规律研究,为控制类似的土质高边坡中使用预应力锚索时的预应力损失提供理论依据。
[Abstract]:China has a large population. In order to make effective use of land resources and mineral resources, urban construction, construction of railways, highways and water conservancy facilities, construction of large-scale factories and mines, and other activities in mountainous areas, are often carried out through high fill and deep digging and leveling of land. In this way, a large number of soil excavations and backfill high slopes are formed. Under the influence of external conditions, slope instability is easy to occur. As a result, the safety of construction projects and people's lives and property is threatened. Prestressed anchor cables are widely used as protective measures on side (sliding) slopes, and the prestressed loss of prestressed anchor cables in soil layer is very large. Therefore, the long-term stability of prestressed anchor cable in high soil slope is directly related to the safety and permanence of protected slope. The reinforcement mechanism of prestressed anchor cable in high soil slope is analyzed by collecting data. Then taking one of the soil high slope and one soil backfill high slope protection project in Xinyuan Jieneng Power Plant as the research object, through the monitoring of the construction process and after construction, combined with the field geotechnical test analysis, The main factors affecting the prestress loss of Anchorage cable are creep of rock and soil, tensioning and locking loss, relaxation of steel strands and influence of external conditions. The influence of soil creep on anchor cable prestress of high soil slope is greater than that of rock slope. The general law of anchor cable prestress loss in soil high slope is obtained, but the prestressing loss of anchor cable in soil backfill high slope is smaller. The reason for this difference is that the compressibility of backfill is low, and the deformation of non-collapsible soil is smaller than that of the former, that is, the long-term action of load is smaller than that of the former, and the overtensioning and supplementary tensioning can make the cable prestress meet the design requirements. Grouting can improve the mechanical properties of high soil slope, and it can be applied to soft soil and crevice developed slope, anchoring technology and grouting measures. It can reduce the loss of anchor cable and stress and improve the stability of slope body. The compaction degree of backfill soil above 90% is favorable and guaranteed for the quality of anchor cable and engineering construction. Through the above research on the law of prestressing loss of anchor cable in high soil slope (especially soil backfill high slope), It provides a theoretical basis for controlling the loss of prestressing force in similar high soil slope when prestressed Anchorage cable is used.
【学位授予单位】：西安科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU476

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