Consider the following statements regarding anchorage of pipelines conveying water : 1. At bends, pipes tend to pull apart 2. At bends, forces exerted on the joints due to longitudinal shearing stresses are enormous and the joints may get loosened 3. To avoid problems by hydrodynamic effects, pipes are anchored using concrete blocks which absorb side thrusts at bends 4. Pipes are also anchored on steep slopes Which of the above statements are correct?

Anchorage or Thrust blocks

• Thrust blocks are anchors placed between a pipe and solid trench wall.

• Thrust blocks should be placed on the fitting in the direction of water flow.
• A thrust block prevents separation of joints and pipe movement by transferring the resultant thrust force at a bend to the undisturbed soil behind the thrust block

Places where anchorage is needed

• Thrust blocks are required where fittings change the direction. Example: ties, elbows, wyes, caps, and valves
• They are necessary at angle points, side outlets, valves, and on steep slopes.
•  The type of pipe joint used determines the necessary anchoring at these points.

Why we use anchor blocks?

• To avoid problems by hydrodynamic effects
• To transfer the load from the pipe to a wider load bearing surface.
• To protect the pipe from the thrust forces acting due to hydraulic forces at the bends such as longitudinal stresses.