The invention discloses a deep foundation pit combination supporting construction method for geology with high
water level and
large particle size sand gravel.
High pressure jet grouting
pile construction is conducted outside a foundation
ditch retaining and protecting
system, by means of a triple placing method,
cement paste is injected into underground soil filling layer and sand gravel gaps, after solidifying, secant
pile wall and retention wall are formed, the underground water is prevented outside the periphery the foundation
ditch retaining and protecting
system, and conditions are created for the construction of a support
pile; when the strength of outer side jet grouting pile meets design requirements, a long
auger drilling cast-in place pile begin to be constructed close to the inner side of the jet grouting pile; after
perfusion pile beings maintained for 15 days, jet grouting pile construction begins to conduct to make up
partial failure of waterproof curtain of the jet grouting pile in construction of retaining and protecting pile, and retaining and protecting strength and water interception effect of the retaining and protecting
system are increased; at last, in an earth excavation process, bar-mat reinforcement sprayed concrete slope protection and construction of
dewatering well, open trench and water-collecting well in the foundation
ditch are completed well, multiple retaining and protecting forms are used for combining construction and interaction. Accordingly, the problems of retaining and protecting the geology with high
water level and
large particle size sand gravel and
processing the geology are solved.