Sewer Culvert Installation Method to Accommodate Underground Construction in an Urban Area with Narrow Streets (The Development of Shield Switching Type Micro-Tunneling Method and the Introduction of Construction Examples)

In recent years, a reconstruction project for sewer 
pipelines has been progressing in Japan with the aim of renewing old 
sewer culverts. However, it is difficult to secure a sufficient base area 
for shafts in an urban area because many streets are narrow with a 
complex layout. As a result, construction in such urban areas is 
generally very demanding. 
In urban areas, there is a strong requirement for a safe, reliable and 
economical construction method that does not disturb the public’s 
daily life and urban activities. With this in mind, we developed a new 
construction method called the “shield switching type micro-tunneling 
method,” which integrates the micro-tunneling method and shield 
method. 
In this method, pipeline is constructed first for sections that are 
gently curved or straight using the economical micro-tunneling 
method, and then the method is switched to the shield method for 
sections with a sharp curve or a series of curves without establishing 
an intermediate shaft. 
This paper provides the information, features and construction 
examples of this newly developed method.

• Osamu Igawa
• Hiroshi Kouchiwa
• Yuji Ito

• Micro-tunneling method
• Secondary lining applied RC segment
• Sharp curve
• Shield method
• Switching type.

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2006 shield tunnels” Japan Society of Civil Engineers Tunnel
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Subcommittee, 2007.
[2] Japan Sewage Works Association,” Design Standard for Sewerage
Micro-Tunneling Method”, Japan Sewage Works Association, 2010.
[3] Japan Sewage Works Association,” JSWAS Rainforced Pipe (RCP) for
Sewerage Micro-Tunneling Method (A-2)”, Japan Sewage Works
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[4] Japan Sewage Works Association,” JSWAS Glass Fiber Rainforced Pipe
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Association, 2013.
[5] Japan Sewage Works Association, "Standard Segment for Shield
Tunneling Method (A-3, 4)”, Japan Sewage Works Association, 2001.