With the acceleration of urbanization, the construction of subways, tunnels and other infrastructure is increasing, and the application of shield technology in underground engineering is becoming more and more extensive. However, the problem of muck slurry disposal generated during the construction of the shield has been plaguing the construction party and the environmental protection department. How to ensure the quality of the project while realizing the environmental protection treatment of muck slurry has become an urgent problem to be solved.
1. The generation and hazard of shield muck mud.
Shield muck slurry is a mixture produced during shield construction, which is mainly composed of soil particles, water, organic matter and chemical additives. During the shield construction, due to the softness of the underground soil or the large excavation area, it is necessary to inject concrete to stabilize the soil around the tunnel. The impurities such as muck and mud generated by the shield machine during the propulsion process will be mixed together to form the shield muck mud. These muck slurries have a higher viscosity, lower density, greater fluidity and a relatively stable solid phase.
If the shield muck slurry is not properly disposed of, it may cause pollution to the surrounding soil, water source, air, etc., affect the ecological environment, and cause potential risks to people's health. At the same time, the untreated shield muck slurry is prone to soil erosion, resulting in land subsidence and damage to surrounding buildings and infrastructure.
Second, the plate and frame filter press treats the shield muck mud.
Plate and frame filter press is a kind of equipment widely used in the field of shield muck slurry treatment. It works on a unique principle that uses pressure to drive the slurry through the filter cloth for efficient separation of solids and liquids. In this process, the water is effectively separated from the slurry, thus achieving the goal of solid-liquid separation.
1. First, the shield muck is screened with a vibrating screen, then deeply cleaned by a wheeled sand washer, and fine sand can be obtained by dewatering through a dewatering screen, and the fine sand is transported to the fine sand accumulation through a belt conveyor.
2. The shield mud washed out of the sand flows into the mud collection tank, and the flocculant in the chemical system is pumped to the deep cone mud separation tank by stirring and the mud in the mud collection tank for reaction, and the sludge and clean water are separated and precipitated after mixing, and the clean water enters the clear water pool.
3. The flocculated slurry enters the plate and frame filter press through the special filter press pump for solid-liquid separation. The dry mud cake is transported to the designated area, and the clean water is discharged and recycled through the filter press. The use of environmental protection technology can effectively reduce the pollution of shield muck to the environment.
The treated solids can be used for landfills, building material manufacturing, and more. Filtered water, on the other hand, can be reused or discharged after proper treatment.
3. Summary. The significance of shield muck slurry treatment is to reduce environmental pollution, protect the ecological environment, and at the same time, it can also make use of some useful components to achieve rational utilization of resources. In the process of shield construction, attention should be paid to the treatment of muck mud and effective measures should be taken to reduce its impact on the environment.