1. Flatness: ± 2cm / m2, smooth and straight;
2. Compaction degree: 95%, after laying the geomembrane on it;
3. Longitudinal and transverse slopes: The longitudinal and lateral slopes should be above 2%. The boundary and structure of the gallery at the bottom of the landfill must be beneficial to the diversion of the leachate;
4. Cleanliness: There should be no sharp objects such as roots, rubble, stones, sputum particles, etc. within a vertical depth of 2.50 cm.
Construction climate requirements for laying geomembranes:
1. The temperature is 5-40 °C. Considering the thermal expansion and contraction of the geomembrane, according to experience, the geomembrane should be laid tight when it is cold; it should be relaxed when it is hot; but it should be avoided in the summer. High temperature at noon.
2. Wind and rain: When the wind exceeds 4 or rainy days, the construction should stop; when the wind is low, the sand film should be used to press the geomembrane to facilitate construction.