摘要
针对顺层边坡降雨模型试验中的监测元器件易失效和支挡结构受力测试困难等问题,尝试采用光纤光栅技术解决以上问题。在推导不同光纤光栅传感器测试原理公式的基础上,结合光纤布拉格光栅(FBG)自主研发了相应的测试元件。在前期研究的基础上,分别构建倾角为40°的有、无支挡顺层边坡开展降雨模型试验,并对坡体位移、框架锚杆和抗滑桩受力等物理力学量的降雨发展特征开展监测。结果表明,基于光纤光栅技术的测试元器件在降雨等恶劣工作环境下仍能够保持较好的工作特性。在降雨过程中大倾角无支挡顺层边坡易发生层间错动现象,但对其施加支挡结构之后,不仅位移变化模式由陡变型转化为缓变型,且层间错动现象得到了控制。降雨过程中边坡支挡结构内力增长速率较快位置由后部逐渐向前部及深部转移,雨后顶层框锚结构内力增长不大,底层锚杆和抗滑桩内力在雨后仍有一定幅度的增长,且在降雨结束后2 h左右才达到稳定状态,可据此确定降雨工况下顺层边坡重点监控的部位及时间。研究成果为顺层边坡模型试验监测及降雨工作特性评估提供了新的思路和方法。
In the rainfall model test of the bedding slope, since it is challenging to install the monitoring components and to measure stress of retaining structures, a fiber grating technology is adopted to solve the above problems. Based on the deductions of different measuring principles of fiber grating sensors, the corresponding experimental components have been developed by combining with the fiber Bragg grating （FBG）. Two kinds of the bedding rock slope with a dip angle of 40°of rock layers are constructed to perform model tests under rainfall conditions with and without retaining. Physical and mechanical characteristics including slope displacement, frame-anchor internal forces and moment of anti-slide pile are monitored. The results show that components of fiber grating technology maintains well in difficult environments. Interlayer dislocation phenomena appear in the bedding rock slope with high dip angle without retaining during rainfall. When the retaining structure is used in the model slope, the displacement model changes from a steep variant to a slow variant, and the interlayer dislocation phenomena are also restrained. The locations of retaining structure where the internal force grow fast transfer from the rear retraining structure to the front and deep portion of the slope. The internal force increases slowly in the anchor at the top of the slope, while increases rapidly at the lower part of the anchor and the pile. The internal force reaches a steady state until about 2 hours after rainfall. It can be used to determine the key monitoring location and time for the bedding slope under rainfall conditions. This study provides new insights and methods for the bedding slope monitoring and evaluation of the operating characteristics under rainfall conditions.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2016年第7期2119-2127,共9页
Rock and Soil Mechanics
基金
国家自然科学基金(No.41502299
No.41372306)
四川省教育厅科研项目(No.16ZB0105)~~
关键词
光纤光栅测试技术
元器件研发
顺层边坡
支挡结构
降雨模型试验
fiber grating monitoring technologies
components development
bedding rock slope
retaining structures
rainfall model test
