When water to be drained and dropping head o f foundation delve are small, filter diversion, duct diversion, well draining an d blind ditch diversion can be adopted.

This article describes the situation of blind drain used in the construction of Laoyemiao-Jining Expressway,and the main form of blind drains.

The paper discussed the blind drain installation,raw materials choosing,construction technology etc.

For example, blind drains were set under bottom board to statically release the floating force of water; dual infiltration technique was used in self waterproof concrete; waterproof layer was added in roof board; isolation layer was installed between continuous wall and lining wall.

To work out variation regularitiesof flow and water depth in blind ditchesduring raining time,hydraulic modelsfor blind drainage system of urban expressway are established for the design and layout of blind drainage system based on researcheson non-saturated permeating of soil and moving regularitiesof flow in crushed stones.

In order to reduce the hazard of seepage in filled slope of mountainous area two paths of designing are proposed and analyzed herein based on the paper of 《Quantitative Analysis of Hazard of Seepage in Filled Slope of Mountainous Area》:one is to set seepage course with gravels and the other is to use blind ditch for guiding the flow.

Therefore,the slope protection measures such as drains as well as blind ditches,are put forward to intercept groundwater and surface water according to the features of the slope.

By installing catch basin(collector well),adding French drain for water draining,such construction problems as unfavorable geology condition drop,drain off water,have effectively been solved in constructio.