Design method for vertical type foundation pit supporting structure

Abstract

The invention relates to the technical field of foundation pit engineering, in particular to a design method for a vertical type foundation pit supporting structure. The design method for the vertical type foundation pit supporting structure is characterized in that the supporting structure comprises a supporting pile and a supporting body. The design method specific to the double-row pile type supporting pile at least comprises the following steps that the supporting body is simplified into a supporting point of the foundation pit supporting structure according to the rigidity; the internal deformation force of the supporting pile and the supporting body under the soil pressure action is calculated; the resistance needed by the supporting body is calculated; and the included angle between the supporting body and the supporting pile and the length of the supporting body are calculated according to the resistance needed by the supporting body. The design method for the vertical type foundation pit supporting structure has the advantages that the vertical type foundation pit supporting structure has the multiple functions of reinforcement, soil blocking and water stopping, restrains deformation of a soil body, improves the stability of the wall of a foundation pit and realizes support-free or barrier-free construction in the pit; the related double-row pile soil pressure distribution theory research is disputed in the rock-soil field for a long time and no general agreement is achieved; monitoring data is the convincing measured data, the calculation mode is improved, and parameters are obtained through back calculation with the monitoring data, so that an effective way is provided to solve the problem.

Description

technical field [0001] The invention relates to the technical field of foundation pit engineering, in particular to a design method for a vertical foundation pit supporting structure. Background technique [0002] At present, the support structure for soft soil foundation pits generally adopts cement-soil gravity retaining walls or bored piles + pit support, but both have their own advantages and disadvantages. [0003] The advantages of the cement-soil gravity retaining wall are: there is no support in the general pit, which is convenient for rapid excavation, and has the dual functions of retaining soil and water stop, but the disadvantages are: weak displacement control ability, difficult to control construction quality, and general economy . [0004] The advantages of bored piles + in-pit support are: it is applicable to a wide range of soil properties and soil layers, and has little impact on the surrounding environment, but the disadvantages are: the cost per meter fo...

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Problems solved by technology

[0003] The advantages of the cement-soil gravity retaining wall are: there is no support in the general pit, which is convenient for rapid excavation, and has the dual functions of retaining soil and water stop, but the disadvantages are: weak displacement control ability, difficult to control construction quality, and general economy

[0004] The advantages of bored piles + in-pit support are: it is applicable to a wide range of soil properties and soil layers, and has little impact on the surrounding environment, but the disadvantages are: the cost per meter for shallow foundation pits is high, and the internal support has a great impact on excavation. Inconvenient, the support must be removed later, affecting the construction period

[0007] 1) In actual engineering, the distance between the front and rear rows of piles is usually dense at the front and sparse at the back. The diameter of the piles can be different, and the length of the piles can also be different. Neither the standard method nor the software based on the standard method can be used to calculate the actual project.

[0008] 2) The normative calculation model considers the shielding effect of the rear row of piles on the soil pressure of the front row of piles, but the distribution of the front and rear row of soil pressure has nothing to do with factors such as the distance between the rear row of piles, and its rationality remains to be discussed

[0009] 3) When the row spacing of the double-row piles is relatively large, the rationality of the soil between the piles as an elastic compression layer remains to be discussed

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