Issues related to impermeability requirements
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For key seepage prevention areas, the environmental impact assessment requires that after implementing seepage prevention measures, the equivalent clay seepage barrier thickness Mb should be ≥6.0 m, with K ≤ 1×10-7 cm/s； Or refer to GB18598 for implementation. I would like to ask everyone what an equivalent clay barrier layer means. Is that right? The requirements for environmental impact assessment are divided into two parts: one is the thickness requirement, namely that of the equivalent clay barrier layer, and the other is the permeability coefficient K of the material. .
Are there any standards related to waterproofing?
I don’t know. . It wasn’t found in the environmental impact assessment
The waterproofing standards are 50108/50208/50345; there’s one more, I forgot it
Refer to the anti-seepage standard of 50108. But it’s still a good idea to consult an environmental assessment company before proceeding, as the specific circumstances vary from place to place, and thus the requirements differ as well
The clay impermeable layer has Mb ≥ 6.0 m and K ≤ 1×10-7 cm/s； It refers to the thickness and the permeability coefficient of the material after compaction; generally, for clay this value is above 0.6 m. Is 6 m an exaggerated figure?
Uh, I still don’t understand: does it mean that according to environmental impact assessment requirements, the permeability coefficient of this impermeable material after compaction should be 10-7 cm/s? The measures for preventing seepage consist of many elements combined together, such as geomembranes, impermeable concrete, and specialized coatings. In other words, the combined water-resistant properties of these materials are sufficient to achieve a value of 10-7 cm/s? Also, the thickness of the clay layer refers to the thickness of the clay that needs to be compacted beneath the concrete pad (I’m not quite sure; does this mean that for every building foundation, it’s necessary to excavate the soil first, then lay a clay layer at the bottom of the pit before adding the concrete pad?)