A kind of sinking method of super large open caisson

Abstract

The present application discloses a sinking method for a super-large caisson, which includes: step S1: dividing the soil at the bottom of the super-large caisson into a blind area and a non-blind area, and calculating the allowable soil borrowing depth Hc' of the soil in the non-blind area; Step S2: Calculate the critical width B' of the soil in the blind area according to the allowable depth Hc' of the non-blind area, and the critical width B' is the critical width when the soil in the blind area is damaged when the super-large caisson sinks; step S3: Continue to take soil downward in the non-blind area until the depth of the formed well hole reaches the allowable soil depth Hc'; Step S4: Take soil symmetrically from the adjacent blind area in the well hole until the width of the soil in the blind area is constant. reduce to the critical width B', at this time, the super-large caisson will rely on its own weight to cut soil and sink; step S5: after the super-large caisson stops cutting downward and sinks, repeat steps S3 to S4 until the super-large caisson sinks The well sank to the design elevation. The application can realize the smooth and safe sinking of super-large caissons.

Description

technical field [0001] The present application relates to the field of caisson construction, in particular to a sinking method for super-large caissons. Background technique [0002] With the continuous increase of the span of the bridge, the scale of the caisson foundation is also getting larger and larger, and the planar length of the super-large caisson is close to 100 meters, and the difficulty of sinking construction control has increased sharply. [0003] Compared with small caissons, the main contradiction of subsidence of super-large caissons has changed from reducing side resistance to reducing end resistance, and the excavation of the soil under the edge of the caisson wall is affected by the caisson partition wall and soil borrowing platform arranged on the top of the caisson. Due to the influence of the blind area, it is difficult to take soil, the resistance at the end of the caisson cannot be relieved, and the sinking of the caisson is difficult, which may easi...

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Problems solved by technology

[0003] Compared with small caissons, the main contradiction of subsidence of super-large caissons has changed from reducing side resistance to reducing end resistance, while the excavation of the soil at the foot of the caisson sidewall is affected by the caisson partition wall and soil borrowing platform arranged on the top of the caisson. Due to the influence of the blind area, it is difficult to take soil, the resistance at the end of the caisson cannot be relieved, and the sinking of the caisson is difficult, which may easily cause problems such as sudden sinking, deflection and sand gushing of the caisson, which seriously affects the structural safety of the caisson, the stability of the caisson and the construction period.

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