Proceedings - 13th International Workshop on Micropiles - 2017, Vancouver, BC, Canada, (ISM, DFI, ADSC)
A Review of Micropiles Beneficial Aspects through a Case History near False Creek, Canada
M. Deriszadeh, M.Sc., Ph.D. and M. J. Kokan, M.A.Sc., P.Eng.
Micropiles, also known as minipiles are a type of deep foundations composed of placed or injected grout and steel reinforcement with diameters of typically smaller than 300 mm. Micropiles have recently gained higher acceptance in geotechnical engineering practice and have been utilized as a foundation solution in numerous applications such as seismic retrofitting, resisting uplift loads, control of settlements and underpinning of existing foundations. This paper presents a case history where micropiles were used as supporting elements for underpinning and controlling settlements of an existing foundation system adjacent to a 15 m shored cut for a residential tower development, located in close proximity to False Creek, in Vancouver, Canada. The existing foundation system, supporting each pier of an elevated viaduct, included a pilecap and a group of cast-in-place reinforced concrete piles with pile tips located significantly above the final excavation grades. The 15 m shored excavation was proposed to be completed directly adjacent to the existing pilecaps. The advantages of using micropiles in controlling the movements of the existing foundations of a sensitive structure (bridge viaduct) will be demonstrated. Laser displacement meters (LDMís) and tilt meters (TMís) were used to monitor the 3-dimensional displacements and rotation of the existing pilecaps during the excavation and shoring. In addition, traditional precision surveys were carried out to verify the data of the automated monitoring system. Monitoring results showed excellent performance for the micropile supported piers in a congested construction area to control the displacement/rotation of the existing viaduct structure adjacent to the shoring walls.
|article #2635; publication #1033 (ISM- 2017)|