Site rail track post-subsidence renewal involves empty pipes or rods filled with or made of easily removable material and run through where plate and layer join.

摘要

Empty pipes (5) are run through left to right directly above the hydraulically bound loadbearing layer (2) and the bearing plate (1) where they join. The pipes are filled with empty removable material or the pipes are replaced by rods of easily removed material. The pipes or rods are of greater diameter than the cable saws but less than 5 cm. Pipes or rods are set 2-20 m apart and in addition to the rail chairs the plate is fitted out with internally threaded inserts (7) which pass through the plate vertically from top to bottom. Saws are threaded through the embankment at the passage formed by the pipe etc so as to part plate from the bearing layer. The plate is then raised to datum level and fresh pipes or rods installed for the next renewal operation etc. The interval between plate and layer is packed with self setting material.