高速公路路基加宽土工格栅加筋优化技术研究

基于分析高速公路改扩建工程新老路基间不协调变形的原因、控制技术方法及控制标准，对高速公路改扩建路基加宽土工格栅加筋优化技术进行了研究。以京港澳高速公路石家庄至磁县（冀豫界）段改扩建工程典型试验段为研究对象，建立了高速公路路基加宽有限元计算模型，分析了施工期路基填筑高度和竣工后15 a的地表附加沉降、附加水平位移和路面横坡比变化规律。采用土工格栅加筋新路基技术，通过改变土工格栅的弹性模量、加筋层数和加筋长度等技术参数，研究分析了土工格栅参数变化对路基表面沉降量及路面横坡比的影响。根据计算结果提出了高速公路路基加宽土工格栅加筋优化设计技术方案，该研究结果为高速公路改扩建土工格栅加筋路基设计提供了技术参考。

Optimization technology for geogrid-reinforced subgrade widening projects of highways

The causes, control methods and standards for uncoordinated deformation between new and old subgrades in highway reconstruction and extension projects are analyzed. According to the typical test section of Shijiazhuang to Cixian (demarcation line between Hebei Province and Henan Province) reconstruction and extension project of Beijing-Hongkong- Macao Highway, a finite element model for subgrade widening of highways is established. The additional settlement and horizontal displacement of ground surface as well as transverse slope ratio of pavement are analyzed during the construction period of new subgrade and after construction of 15 years. The geogrid-reinforced technology for the new subgrade is used in this project. The geogrid modulus, reinforced layers and reinforcement length are changed during calculation. The effects of these parameters on surface settlement of the subgrade and transverse slope ratio of pavement are studied. Based on the computational results, the optimization design technology of geogrid-reinforced subgrade widening for highways is presented. The test results can be used as a reference for future studies and design of geogrid-reinforced subgrade in highway reconstruction and extension projects.