CONNECTION METHOD OF PIPE FOR CURVE BORING AND JOINT FOR CONNECTION

• Main Authors: NIWA KAZUO, MIKI AKIO, KASUYA TARO, OBATA TSUNEO, MARUYAMA TADAKATSU, MIKI HAJIME
• Format: Patent
• Language: English
• Published: 17.02.1998
• Edition: 6
• Subjects: EARTH DRILLING; EARTH DRILLING, e.g. DEEP DRILLING; FIXED CONSTRUCTIONS; GALLERIES; LARGE UNDERGROUND CHAMBERS; MINING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR ASLURRY OF MINERALS FROM WELLS; SHAFTS; TUNNELS

PROBLEM TO BE SOLVED: To ensure the connection property and improve the work efficiency by arranging and connecting a joint made of shape memory alloy in a stepped part which is machined down to the depth in a scope of specific wall thickness over predetermined length of an outside diameter of a succeeding arclike curved pipe to be connected. SOLUTION: A rear end part of an arclike curved pipe 10 which precedes and a tip part of an arclike curved pipe 10 which succeeds are connected mutually. At this time, a stepped part is machined down to predetermined depth of 1/3 to 2/3 of wall thickness of the pipe 10 over fixed length L1 of 1/4 to 1/2 of an outside diameter in a connection end part of the pipes 10, 10 in advance. Next, when they are connected together with the advance of digging, a joint made of shape memory alloy 20 is arranged in a stepped part A for connection. Moreover, a tapered part like truncated conical base is formed over the fixed length of 1/2 to 1/1 of the outside diameter in either of connection end parts of the pipes 10, 10 in advance. In this case, a tapered part which becomes thinner toward a tip of gradient of 1/20 to 1/80 is formed, and a tapered recessed part having the length which corresponds to the other end part and gradient is formed.