Great progress has been made in the construction of laopinggang tunnel through the Mujia high speed railway

At 10:08 on the 12th, with the last blast, laopinggang tunnel of section 7 of Mujia high speed railway was successfully completed, laying a solid foundation for the subsequent girder erection and track laying operation, and new progress was made in the construction of Mujia high speed railway The laopinggang tunnel built by Shanghai Engineering Bureau of China Railway is located in Qifeng forest farm, Huanan County, Jiamusi City, with a total length of 1569m and a maximum buried depth of 98m. It is designed as a single hole double line tunnel. The tunnel is located in the alpine area of Northeast China. The maximum freezing depth of soil is 2.4m, the geological conditions are complex, the surrounding rock is relatively broken, and the water content is large, which brings great challenges to the construction

since the tunnel entered into the main tunnel construction on April 8, 2018, the project department has reasonably optimized the construction organization design, planned various construction measures in advance, and adopted a variety of modern large-scale tooling to ensure that the tunnel construction quality meets the requirements of the fine works of the construction unit in view of the complex geology, high-quality construction process requirements and unusually tight construction period. In the construction process, the three step temporary inverted arch method, the three step method and the step method are the main construction methods. In the process, strict process control is required to ensure that each process meets the design and specification requirements

in view of the high risk of construction, the project department implements the leadership guarantee system and night inspection system, and the project department and division level leadership work are implemented in key processes. Through the management and control of key processes such as arch frame installation, initial support and shotcreting, excavation size and concrete pouring, the quality and safety of the tunnel are ensured, and the smooth connection of the tunnel is effectively guaranteed

up to now, 4 tunnels in the 7 section of Mujia high speed railway of Shanghai Railway Engineering Bureau have been through 3, with 4398.9 meters of tunnel excavation completed, accounting for 96% of the total. Pier body construction and subgrade filling in the bid section have been completed, and other works such as beam making and beam erecting are also being accelerated. (Zhai Shenghui, di Jie)