Abstract: The disclosure belongs to the field of tunnel construction technologies, and more particularly, relates to a construction method for making a water-rich sand layer shield over cross an existing line and underneath cross a sewage push pipe at a close range. The method specifically includes the following steps of: S1) before construction, using MIDAS GTS NX software and FLAC3D to optimize a tunneling scheme antecedently by numerical simulation to determine a part of unfavourable stress; S2) tunneling a test section, the test section being a stratum crossing a front shield direction by 45 m to 60 m; and S3) performing shield crossing construction, wherein a shield crossing construction process includes the steps of: 1) controlling a soil pressure; 2) controlling a shield thrust; 3) performing synchronous grouting; 4) performing a ballasting measure in a tunnel; and 5) performing automatic monitoring in the tunnel.

Abstract: A tool configured for adjusting a plurality of pressing heads of an auxiliary welding machine and a method for operating the same are disclosed. The tool includes: a support; a limiting mechanism disposed on the support, wherein the limiting mechanism has a limiting groove for receiving a top end of at least one of the plurality of pressing head. It is possible to adjust the plurality of pressing heads of the auxiliary welding machine more conveniently and accurately using the above tool.

Abstract: A tool configured for adjusting a plurality of pressing heads of an auxiliary welding machine and a method for operating the same are disclosed. The tool includes: a support; a limiting mechanism disposed on the support, wherein the limiting mechanism has a limiting groove for receiving a top end of at least one of the plurality of pressing head. It is possible to adjust the plurality of pressing heads of the auxiliary welding machine more conveniently and accurately using the above tool.