For the Victoria Island Conveyance
Canal Pipeline near Discovery Bay, CA, Malcolm
Drilling constructed access shafts for micro-tunneling
a 96" diameter pipe under the Old River.
Using a Bauer BG 40 equipped with a CSM Attachment
and BCM 10 cutting wheels, MDCI soil mixed overlapping
CSM panels (3.3ft x 9.2ft) in a circular pattern
to construct the access shafts.
The CSM panels provided shoring for the excavation
of each shaft and also worked as a cut-off wall
to prevent water from entering the shaft. Excavation
continued in the dry despite being 60 ft below
the water table.
Panels for the receiving shaft were mixed to
a depth of 58ft and the shaft was excavated to
a depth of 50ft. Panels for the jacking shaft
were mixed to a depth of 103ft and the shaft was
excavated to a depth of 95ft. system.