The Optimization Design Of Dewatering And Draining At Zhangzizhong Station Of N.O.5 Subway In Beijing

In the article, though the analysis study of underground No.5 Zhangzizhong station engineering geological condition hydrography condition and construction condition, some factors were studied, such as, geological condition surrounding environment construction condition total construction plan. Summarizing in the precipitation design it is necessary to optimize and adjust the principium design according to scene fact instance and construction experimentation instance, precipitation design is a dynamic control process, the optimization of precipitation design is in proper sequence process, its aim is to improve the quality of precipitation well reduce the cost of engineering project protect and save water resource and avoid the ground sedimentation pipe distortion crack of construction etc because of precipitation. So bringing forward drain seep well and seep welK decompression well design project. The followings is particular design thoughts:(1)Common precipitation is designed to drain seep well, the upper backwater and diving were transported to bear press water layer to drain, increasing the length of well and penetrate bear press water layer, improving the effect of self-seep, then falling the mix of upper backwater, diving and bear press water, making sufficiency use of the drain capability and great season change of bottom bear press layer, controlling the quantity of underground water though the inspecting to mix water level and saving underground water resource..(2)Minish the well space and increase transflux routeways upper backwater and driving, especially setup precipitation well and drain residual water at the bottom of diving layer.(3)The filtration material of outboard well pipe was optimized according to the character of containing water layer and stratum and to reduce the construction cost. Because the diving water level is below 18.0m, the underground water in upper 15.0m water layer scatter everywhere and exist in format of upper backwater, the action of well pipe filter material is only the seep routeways of upper backwater, though the filter material, the underground water self-seep the precipitation well. The filter material under divingis acted not only the water pipe, but also filter in resisting the sand outflowing from water. According to this, the 3-7m detritus is filled in the upper of 15.0m, its form is slice and pointedness and cost cheaply. In the bottom of 15.0m gravel is used. (4)The structure pertain to station, such as passageway ventilation, its foundation is shallow, about 10m,in addition its position is traffic road, so drain well will completely be designed to lead seep well, its aim is to lead upper backwater and diving to the bottom bear press water layer, thus the level of mix water is much lower than elevation of the structure bottom board, in the rainy season, it can prevent level of underground water from rising lest affect foundation pitch excavation. Its superiority is rather obvious: 1 leave out drainage pipe, the setting of power supply circuitry reduce the engineering cost, only to need to set temporary water supply pipe. 2. Don't need to excavate in the road, not only reduce traffic affecting, but also depress safety venture that construct in the road; 3. Because of self-seep, don't install water pump, reduce the cost of electricity in the course of drainage as well as decrease consume of underground water resource, protect environment, save water resource, reduce ground sedimentation; 4. By reason of completely setting 3-7mm detritus around the well pipe, can also save construction cost.(5)The types of pipe line around precipitation well are excessive and denseness, in the course of construction, it is necessary to adjust the precipitation well level according to scene fact instance to assure the construct safety and precipitation effect.(6)The precipitation engineering is assistant working procedure of structure construction, assort actively structure construction, when total structure construction project need to be adjusted, local obturated precipitation area...