| 摘要 |
In the process for the construction of trenches in ground containing water and/or gas wherein a trench is due in said ground, support media is introduced in said trench to support the walls formed by the treching, vapor or water conduit means are placed in the trench and the trench with this support media is back-filled with particular material to dispose and remove the support media from the trench, the improvement comprising employing as said support media a hydrated cross linked acrylic polymer.
|
