Outline
High Capacity Micropile
Execution Process
Seismic Retrofitting of Existing Pile Foundation
under the Bridge
Seismic Retrofit Construction of The Water Service Station
High capacity micro piles (HMP) combine the drilling technology used by the ground anchor method and the pressurizing injection technology of grouting. HMP uses high strength steel pipes in addition to deformed bars as reinforcement, which ensures a high bearing capacity. They can be used in narrow spaces and where overhead clearance is limited
HMP are installed using a small drilling machine. The HMP uses deformed bar and the steel pipe reinforcement, and is completed by the grout injection.
Outline of High Capacity Micro Pile
Grout
Deformed Bar Joint
Top of Footing Bearing Plate
Cased Upper Part (section A-A')
Steel Casing Pipe Joint
Drill bit
Steel Casing Pipe
Pile Uncased Bond Part (section C-C')
C-C'
A-A'
Total HMP Length Steel Casing
Casin
g Plu
nge
Length
Pressure Grouted HMP Bond Length
Cased Upper HMP Length
Top of Pile Part
Non-steel Casing
Deformed Bar
B-B' Casing Plunge Bond Part
(section B-B')
Grout
Deformed Bar
Deformed Bar
Centralizer
HMP ; High Capacity Micropile
Grout
Pile Uncased Length
Soft Ground
Bearing Stratum
Deformed Bar
Grout
Execution Process of HMP
、 Water or air Inner rod
Deformed bar Inject grout under pressure
Adding HMP steel casing Bearing plate
Adding HMP steel casing
Grout
Remove inner drill bit & rod
① ② Place
deformed bar ③
Initial injection ④ ⑤
Reinserting HMP steel
casing ⑥
Treatment of pile head ⑦
Remove temporary casing, inject further grout under pressure as applicable Excavation
(casing boring)
HMP steel casing
Remove temporary casing
Bearing Stratum
Soft Ground
