Numerical Simulation Analysis of Hydrothermal Change of Subgrade by Seepage Drainage Geogrid Under the Effect of Asphalt Mixture Freeze-Thaw Action

In seasonal frozen soil area, the engineering problems caused by the excessive moisture content of the subgrade soil are widespread. In view of this phenomenon, author proposes to employ a new type of research and development of the seepage drainage geogrid (SDG) to cool and drain the soil. Through indoor model test, after two freeze-thaw cycles, the experimental comparison of the size and laying method of various SDG was carried out. The test result shows that the model with a natural grit layer has the most drainage effect. While, the model contains two layers of interconnected grilles has the best cooling effect. The indoor model test is simulated by accurate numerical simulation. The simulation results are compared with the indoor test results. The fitting results of the two results are very high, which provides theoretical support and data guarantee for the application of seepage drainage grille to strengthen the roadbed in the cold road.

Detection of Pipeline Deformation Induced by Frost Heave Using OFDR Technology

Oil and gas pipelines are critical structures. For pipelines in the seasonal frozen soil area, frost heave of the ground will result in deformation of the pipeline. If the deformation continually increases, it will seriously threaten the pipeline safety. Therefore, it is important to monitor the deformation of the pipeline in the frozen soil area. Since optic frequency–domain reflectometer (OFDR) technology has many advantages in distributed strain measurement, this paper utilized the OFDR technology to measure the distributed strain and use the plane curve reconstruction algorithm to calculate the deformed pipeline shape. To verify the feasibility of this approach, a test was conducted to simulate the pipeline deformation induced by frost heave. Test results showed that the pipeline shape can be reconstructed well via the combination of the OFDR and curve reconstruction algorithm, providing a valuable approach for pipeline deformation monitoring.

Analysis of main points of channel freezing-thawing disease in cold region and influence of channel base soil on the disease

The frozen soil area in China is more than two thirds of the total territory, so the problem of frost heave is obvious. Especially in northeast, northwest, north China and other cold regions, the problem of frost heave of hydraulic structures is very common. Canal is a common hydraulic structure in agricultural water, which is affected by seasonal frozen soil and may cause problems such as lining damage, seepage and irrigation efficiency. Therefore, this paper mainly summarizes the necessity of research on channel freezingthawing damage, the research direction of channel freezing-thawing damage, and expounds the influence of seasonal frozen soil on freezing and thawing diseases in cold regions by taking the particle size of saturated soil based on channel as an example.