Karst topography, common large volume processing

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Karst topography, common large volume processing and construction methods cave

This approach is not for the hole body of surface changes with the seasons of the cave can play a role in governance. However, most of these caves the surface changes with the seasons are changing. Such as the use of this treatment there will be some shortcomings as follows: (1) move up and down the water level in reinforced concrete plug will cause pressure imbalances following plug on the stability of reinforced concrete threat; (2) If the water table rose severe, resulting in Hydraulic here is too large, underground reinforced concrete plug will be up Dingfan caused by accident; (3) As the block here, when the water flow rate increases, will increase the groundwater on the impact of other weak areas, and cause other local collapse. These are the main causes of unsuccessful treatment. 3.2.3 The approach adopted now (1) the theoretical basis: As the body of liquid such cave hole and change with the seasons, it must be considered in the treatment liquid flow channel, the method can not be taken to seal treatment, can only be filled with loose material. As the amount of filler more fill the bottom not only to bear the weight, but also bear the weight of the mud after washing, so the cave at the bottom to set the large volume of reinforced concrete shield, and can not be blocked, water can make freely up and down the penetration. While also taking into account the washing can not penetrate the mud after the river, polluting the environment, the surface must be filtered. (2) Construction of treatment: 1) the general selection process such caves in the dry season, the water table is lower. Drain hole with a pump groundwater body, exposing underground fissures. If the hole to deep, can not reveal cracks, put the liquid pumped to a narrow cave at the following, to facilitate construction on the line. But must improve security measures to prevent construction workers fell into the groundwater, causing accidents. 2) cleaned stenosis loose, hanging upside down and the sudden sharp rocks, and then a good support base template. Drill template diameter 100mm, 300mm vertical and horizontal spacing of the holes are used to water seepage, the hole blocked with a plastic tube to prevent the concrete block holes, and then arranged reinforcement. Here according to design requirements, the lower part of June 2006 Gezheng Hong karst topography, common large volume processing and construction methods cave laid 45 424 @ 300 steel mesh, the upper towel laid 18 @ 300 steel mesh, protective layer thickness of 30mm , concrete thickness of 1m, depending on the length of the field of reinforced concrete situation to be. Then placed qlo8 × 5 of the pipe as the tube, the number of ventilation tube to set the size of the cave, and finally C20 pouring concrete to form concrete baffles. In the initial setting of concrete plastic tube pulled aside before the holes. ... 3) in the hole all the snorkel body connection, and connected to an external ventilation tube, good anti-corrosion. 4) meet the required strength of reinforced concrete, etc., and then on the hole to fill. Fill in the following order: first the stone filled with 300mm thick, and then filled with 300mm thick gravel, and finally filled with 300mm thick gravel. Laid in the gravel 400g / m of geotextile layer, fill in the geotextile on 300mm thick protective layer of gravel, 300mm thick gravel and then fill the remaining space filled with a large stone to the hole, leveling with crushed stone and gravel, surface spread 400g / m of geotextile fabrics together, the above shop miscellaneous fill protection. Figure 3 shows. Figure 3 contains the construction method of underground caverns 3.2.4 precautions Construction (1) the location of reinforced concrete block to choose the right pull, usually selected at the deep and narrow, and the bedrock to complete, if the cave has multiple fracture zone, each zone should be fractured block, pull the block before the construction placed in the bezel around the chisel at the trough, the baffle inserts into the tank, baffles can increase the stability and material savings. (2) a reserved port can not be too large baffle to prevent the filling of the stone blocking the reserved port card. (3) bezel filler filler must be mastered in order to prevent the filling geotextile damage, resulting in the mud leak. Inside the cave, and we should try compacting the fill material to prevent collapse due to force crack the top geotextile cause leakage, while the laying of geotextile geotextile fabric when pleating, to prevent being pulled by the force split. (4) The ventilation tube can not block, air leakage can lead to excessive air pressure inside the cave, causing the overall collapse of the upper structure Dingfan. 4 Conclusion and construction of the above treatment is in many instances failed summed up. There are now using the above approach to the mud cave libraries have been used for many years, there have been no instances of one collapsed pollution of the environment. Treatment by this method proved to be successful cave, bringing good economic and social benefits. References: [1] Xiezun Yuan, and the first side. Construction 【M], Beijing: China Building Industry Press, 1989. [2] GB50204-2002, Concrete Construction Quality Acceptance of [s].
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