1. Slope preparation
   
   
   Check the dimension of the mattresses assembled to be sure that they conform to the surveyed drawing. Remove the obstacles which may damage the mattress such as sharp stones,vegetation and stumps etc.
   Finish the surface to be even.

• Maximum gradient 45°
  If the toe of the slope is 50 cm or more underwater, velocity flow should be
  reduced to less than 1.5m/sec.
• Upper anchor trench: Excavate a trench (depth about 50 cm)at a point 50 cm
  away from the top of the slope.
• Lower toe trench: For river bank protection,excavate a trench(depth 1.0 to 1.5m)
  at the toe of the slope.
• Flank trenches at both sides: Excavate flank trenches(depth about 1.0m)at both upstream and downstream ends of the installation,whether or not extension of the revetment is anticipated. The design of anchor,toe and flank trenches are determined according to the nature of the soil, hydraulic considerations and site conditions.

2. Placement of the mat
   
   

• For installation in-the-dry, start by placing the mat over the lower part of the slope at the downstream end of the structure. For underwater installation, start mattress placement from the upstream end of the installation.
• Starting from the toe of the slope,spread the mattress over the entire slope,taking up slack at the top of the slope where the mat is positioned with chain hoists and pipes.

3. Injection of mortar or concrete
   
   

Start injection of mortar or concrete through the injection mouth at the lowest point of the mat. After starting injection,please handle the chain hoist to adjust the slack of the mattress in accordance with the progress of injection. When the mortar or concrete is sufficiently injected into the top of the mattress,stop the injection work and bind the rope at the injection mouth.
Capacity of mortar or concrete injection pump: 10m³/hr. or more
Pressure at the nozzle: about2kg/cm².
Piping hose(swing type):about diam.:50mm,about length: 20m.
(Position the pumping truck to assure minimum hose length for maximum operating efficiency.)
Choke(taper)tube: about diam.:10cm-5cm,length: about 2m with joint at both ends.

4. Completion
   
   

• Finishing
  Sprinkling(washing,curing)the surface with water. Filling the space between mat and existing structure with stiff consistency concrete.
  Back-filling with sand,soil,cobble stone, toe protection block,etc.
• Curing