光纤光栅植入式智能土工格栅传感理论及其路基灾害预警方法研究

The monitoring, precaution, and early-warning of subgrade geological hazards are critical to the safe construction and operation of road engineering. In this project, sensing theory of a Fiber Bragg Grating (FBG) embedded smart Geogrid and its early-warning methodology for subgrade geological hazards will be studied in detail. By embedding FBG into the Geogrid which is the most widely used Geosynthetics, the proposed multi-functional smart Geogrid can be used for enhancement and monitoring in subgrade engineering. Firstly, strain transfer mechanism of smart Geogrid will be studied, and the smart Geogrid with orthogonality embedded FBG nodes will be designed for accurate measurement of two dimensional strains. Then, smart Geogrid based spatial three dimensional deformation reconstruction theory is proposed for the deformation field sensing of subgrade. To set up the theory framework, two inter-related tasks - curvature measuring methods of proposed smart Geogrid and spatial shape reconstruction algorithm based on piece-wise curvature - will be investigated. In the meantime, the study on the deformation synergy between smart Geogrid and subgrade will be performed. And a novel deformation field sensing methodology based on the proposed FBG embedded smart Geogrid for subgrade engineering uses will be formed. Additionally, a multisource sensing system for subgrade engineering monitoring will be set up, and the multisource sensing and comprehensive early-warning methodology based on proposed smart Geogrid will be studied in detail. Finally, field testing will be conducted for verifying the feasibility and reliability of the deliverables of the project. There is a great theoretical and practical contribution to the development of smart Geosynthetics, and it is of great significance to the safety monitoring and early-warning of subgrade geological hazards.

路基灾害的监测、预防与预警是道路工程建设亟待解决的关键科技难题。针对该问题，本项目以路基工程最为广泛应用的加筋材料“土工格栅”为载体，研究适用于路基工程中集”加筋”与”传感”功能于一体的光纤光栅植入式智能土工格栅传感理论及其路基灾害预警方法。首先，通过应变传递机理及正交植入光纤光栅的土工格栅二维应变耦合机理两方面的研究，实现基于智能土工格栅的二维大应变高精度测量方法；然后，研究智能土工格栅曲率高精度传感方法与曲率递推空间形态重构算法，建立智能土工格栅空间三维变形重构理论体系，同时研究智能土工格栅与路基协同变形特性，形成基于光纤光栅植入式智能土工格栅的路基变形场传感新方法；最后，组建路基灾害多源信息感知系统，建立基于智能土工格栅的路基灾害多源信息感知与综合预警方法，并选取典型的工程现场进行验证性试验。研究成果对填补智能土工织物理论研究空白，解决路基灾害监测及预警问题具有重要意义。

随着我国交通强国战略的实施，道路、交通等基础设施建设快速发展，路基等基础设施的全方位监测与安全状态评估是亟待解决的关键科技难题。本项目以变形场、应变等表征路基安全的关键参量监测为出发点，以路基工程最为广泛应用的加筋材料“土工格栅”为载体，研究集”加筋”与”传感”功能于一体的光纤光栅植入式智能土工格栅传感理论及其路基灾害预警方法，并取得了重要进展。揭示了土工格栅与光纤的多层应变传递机理，研究了光纤光栅二维应变传感方法，明确了正交植入土工格栅二维应变的对不同荷载条件的响应规律与耦合特性，建立了基于盲源分析的温度应变分离方法，解决了基于智能土工格栅的应变感测难题。进而，研究智能土工格栅曲率高精度传感与连续化方法，研究了智能土工格栅变形场原位修正方法，突破了基于有监督学习和无监督学习的智能土工格栅变形场传感方法，构建了土工格栅变形重构方法系列；最后，组建智能土工格栅自修复传感网络与多源信息感知软硬件系统，开展了模型试验及现场试验，验证了本项目方法及系统的有效性，最终形成了基于智能土工格栅的路基等基础设施灾害多源信息感知与综合预警方法及软硬件系统