复杂岩土环境下预应力锚固体系长期性能演化规律研究

Pre-stressed anchored cables are widely used around the world as an effective anchored method. Large quantities of these pre-stressed anchored cables have been put in use in key life engineering projects, so what about their service life and whether they may become a big trouble in these projects once they lose the due effectiveness. It is a key to solve the confuse by revealing the evolution mechanism of pre-stressed rock anchor system. Two main research techniques would be applied in this project , which are analyzing the failure pre-stressed anchored cables worked in multi-level tunnel and simulated environment corrosion test. Through analyzing the failure cable samples , the real data close to the field engineering can be achieved . The study work will be performed in this step. Firstly , the failure cables collection work will be done in Qishan Coal Mine multi-level tunnel. And then based on the analyzing results of the failure cables the durability evolution process can be divided into several stages . Secondly, the accelerated corrosion test will be done to reappear the long-term performance evolution stages. According to the achievements of simulated environment corrosion test, damage evolution model will be established. After that the evolution model will be embedded in numerical cable model unit. Finally, all the achievements will be verified in the underground powerhouse project of JinPing first level hydropower station. Results of the project has great engineering significance and economic value .

预应力岩锚在岩土工程领域应用广泛，且使用数量巨大。这些作为永久支护的加固措施一旦失效将对工程造成难以估量的损失。岩土环境条件复杂难以模拟和锚固系统失效样本少的问题一直制约着长期性能领域研究的进展，大量反映真实工作环境的预应力岩锚失效样本的获得和分析是揭示岩锚系统长期性能演化机理的关键。本项目以煤矿多水平巷道运行中产生的大量失效锚杆索样本收集和分析为研究基础，实现对预应力岩锚长期运行失效的一比一现场分析，提出岩锚失效模式、划分预应力岩锚系统的长期性能演化阶段；同时通过室内拟环境加速腐蚀试验，再现长期性能演化过程；基于抗拉强度试验和损伤机理分析，建立预应力锚固长期性能损伤演化模型，揭示预应力岩锚长期性能演化机理。将损伤演化模型嵌入岩锚数值分析单元，提出数值分析和定性分析结合的预应力岩锚长期性能评估方法。最终，研究成果将结合锦屏一级水电站地下厂房支护长期性能评估工程进行验证。

岩土工程锚固技术是当前岩土工程领域的一个重要分支，以其高度的有效性和优越的经济性，在能源、交通、水利及城市建设领域得到广泛应用，尤其在众多国家大型工程中发挥了重要作用。预应力岩锚在岩土工程领域应用广泛，且使用数量巨大。这些作为永久支护的加固措施一旦失效将对工程造成难以估量的损失。由于锚固类结构所处工程环境的复杂性和地下工程的隐蔽性，以及锚固系统失效样本少的问题一直制约着长期性能领域研究的进展，大量反映真实工作环境的预应力岩锚失效样本的获得和分析是揭示岩锚系统长期性能演化机理的关键。..本项目以多个失效锚杆索样本收集和分析为研究基础，实现对预应力岩锚长期运行失效的实例分析，提出岩锚失效模式、划分预应力岩锚系统的长期性能演化阶段。同时通过大量室内加速腐蚀试验、系统的腐蚀试样的物理化学性能等试验和损伤机理分析， 建立预应力锚固长期性能损伤演化模型，揭示预应力岩锚长期性能演化机理。将损伤演化模型与锚固系统安全性和耐久性相结合，提出预应力岩锚长期性能评估方法。并结合实际工程开展了应用研究，研究成果在多项重大水利工程中得到了应用，在工程建设和工程安全评估方面发挥了重要作用。本研究对预应力岩锚工程的安全稳定评价及性能衰变评估具有重要的理论意义和现实价值，同时能指导工程设计和施工，具有较高的经济价值。