Patent ID: 7341403
Filing Date: 2008-03-11
Classification: G02B,H02G

Abstract:
1. A construction method of an information-communicable underground pipe, characterized by comprising the steps of: inserting a sheath pipe into a main pipe through a manhole, said main pipe and a branch pipe connected to the main pipe being comprised in an underground pipeline, the sheath pipe comprising a main body provided with a first empty room for installing a communication cable thereinto and a high-strength low-elongation material element which is integrally provided in said main body along the lengthwise direction of the main body; fixing said sheath pipe in substantially upper part inside the main pipe by fixing said high-strength low-elongation material element onto the inner wall of said manhole by applying tension thereon; inserting a guide conduit into said main pipe, after the step of fixing said sheath pipe inside the main pipe, the guide conduit being formed with a fitting part with which the guide conduit can be fitted to said sheath pipe in order that said guide conduit is supported by said sheath pipe and a second empty room for inserting a branch communication cable thereinto, wherein a branch tension conduit to be inserted with said branch communication cable is branched off from the guide conduit, and the branch tension conduit is in communication with said second empty room at the position corresponding to the connection portion between said branch pipe and said main pipe; and installing said guide conduit inside said main pipe by pressing said guide conduit against said sheath pipe from beneath in order that said fitting part of said guide conduit is fitted to said sheath pipe, and installing said branch tension conduit inside said branch pipe.