Thick Alluvial Freeze Wall Deformation And Freezing Pressure

Coal source is an important energy in China, in order to satisfy the development of national economy, the need of coal resource under the deep alluvium become more and more impendent. In recent years, the most of new shaft need to cross the deep alluvium. Many problems such as the fracture of freezing pipe occur in the artificial frozen alluvium due to the thick frozen alluvium and the large deformation of the soil wall developing. All these problems decrease not only the pace of the shaft construction, but also result in the shaft submerging. Therefore we face with challenge in related theory and key engineering technology, and we must study them to satisfy the methodology of engineering design and construction in the thick artificial frozen alluvium.The main purpose of paper is to study the main shaft for the Wanfu (alluvial thickness of 750m, the freezing depth 894m), and study the deformation of the frozen soil wall and the regularity of frozen pressure, and carried out the structural safety of the wall.This article reviews the status of freezing shaft, and use the large-scale engineering software ANSYS to simulate actual project. Through contrast the numerical results and the measurement results to examine correctness of the numerical model. Then establish a different depth and different excavation section height, and total of 9 models were calculated and analyzed. And also studies the security of frozen soil wall and the law of frozen pressure. This article draws the following main conclusions and results:(1)The radial displacement of frozen wall section in the excavation was unevenly distributed within the high, middle large,up and down small. A formula is proposed for expressing the relationship of the maximum radial displacement of frozen soil wall.(2)In the actual construction process can calculates the depth of excavation section of high security by the different clay.(3)As the design of the main mine shaft of Wanfu is according to the traditional method, in this paper, use finite element method to demonstrate the safety of the structure of the wall. (4) Obtained the formula of the frozen pressure with depth on the the main mine shaft of Wanfu.All of these results have reference value to the actual project.