Application Study of the Geotextile - Graded Gravel - Geomembrane Composite Drainage Layer in Subgrade Construction

The moisture content of subgrade soil increase will lead to soil strength and modulus decrease, the thesis proposes geotextile - graded gravel - geomembrane composite drainage layer solution, for raw materials in different areas, proposes different composite drainage layer layout scheme, and the technical specifications requirements of raw materials. Test section is constructed, analyses the composite drainage layer construction technology carefully, and humidity sensors are planted in the drainage layer, in which the test data show that: after setting the composite drainage layer, subgrade moisture is less affected by seasonal rainfall, humidity change is always in a lessor extent, water stability of the subgrade is increased significantly.