Method of estimation on underlying tunnel and foundation rebound in excavation of foundation pit

A foundation and foundation pit technology, applied in excavation, foundation structure engineering, on-site foundation soil survey, etc., can solve problems such as not considering the influence of unloading additional stress calculation

Inactive Publication Date: 2013-07-17
TIANJIN MUNICIPAL ENG DESIGN & RES INST
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Problems solved by technology

[0047] (1) In the calculation of the unloading additional stress of the soil rebound layer sum method, the influence of factors suc

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  • Method of estimation on underlying tunnel and foundation rebound in excavation of foundation pit
  • Method of estimation on underlying tunnel and foundation rebound in excavation of foundation pit
  • Method of estimation on underlying tunnel and foundation rebound in excavation of foundation pit

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Embodiment Construction

[0084] The present invention is further described as follows in conjunction with accompanying drawing and specific embodiment:

[0085] 1. Theoretical calculation

[0086] According to the calculation of the foundation pit engineering case of the North Square of Tianjin West Railway Station, the engineering geological conditions are as follows:

[0087] This project adopts open-cut construction method. The north square project is a basement floor with partial two-story structure. The foundation pit of the north square is about 316m long from east to west (including about 645m east-west length of the ramp), and about 25-165m wide from north to south. The U-shaped trough of Ziyahe South Road is 409m long and 28m wide. figure 1 shown.

[0088] Cement mixing piles and SMW piles are used as the enclosure structure and water-stop curtain around the foundation pit. in:

[0089] 1) The excavation depth of the foundation pit of the social parking garage is about 4m, and the east a...

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Abstract

The invention relates to civil excavation engineering technology and aims to better predict the rebound caused by foundation pit excavation by comprehensively considering the spatio-temporal effect in soil mass unloading process and the upheaval of the foundation and the tunnel under the condition of foundation reinforcement for the foundation pit. According to the technical scheme, a method of estimation on the underlying tunnel and foundation rebound in the excavation of a foundation pit includes the steps of firstly, calculating residual stress influence depth hr under foundation reinforcement, namely determining unloading influence depth after foundation pit excavation under foundation reinforcement; secondly, correcting according to a soil mass unloading modulus formula and according to finite element calculation results to determine unloading modulus of the soil mass below the excavation face of the foundation pit; and thirdly, calculating the unloading stress average and the corrected soil mass unloading modulus to obtain the magnitude of foundation rebound in the range of residual stress influence depth, and obtain rebound deformation of the underlying subway tunnel. The method is mainly applied to civil excavation.

Description

technical field [0001] The invention relates to civil excavation engineering technology, in particular to a method for estimating springback of a tunnel under excavation of a foundation pit and a base. Background technique [0002] At present, there are many calculation theories at home and abroad to predict the deformation of the underground subway caused by excavation of foundation pits. However, whether these theories can better reflect the actual situation is restricted by many factors. Affected by construction factors in many places, it is difficult to determine the calculation parameters accurately, and each calculation theory has its scope of application. In addition, in soft soil areas, the calculation of foundation pit deformation needs to consider the influence of time and space effects. It is generally believed that in soft soil with rheology, the deformation of foundation pits (deformation of walls and soil) increases with time. And growth, the spatial effect of...

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Application Information

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IPC IPC(8): E02D1/00E02D17/02
Inventor 张启斌韩勇王淳郑磊杨文发康娟萍韩纪强马兆强阎澎旺霍知亮
Owner TIANJIN MUNICIPAL ENG DESIGN & RES INST
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