Study on Deformation Law of Deep Foundation Pit with the Top-Down Method and Its Influence on Adjacent Subway Tunnel

Joint Authors

Gui, Yue
Qin, Xiaqiang
Zhao, Zhenxing
Wang, Jianfei

Source

Advances in Civil Engineering

Issue

Vol. 2020, Issue 2020 (31 Dec. 2020), pp.1-15, 15 p.

Publisher

Hindawi Publishing Corporation

Publication Date

2020-12-01

Country of Publication

Egypt

No. of Pages

15

Main Subjects

Civil Engineering

Abstract EN

Based on a long-term comprehensive instrumentation program, the performance of an excavation pit constructed by the top-down method in downtown Kunming was extensively examined.

The measured excavation responses included the deflections of diaphragm wall, vertical column movement, slab axial force, building settlement caused by ground deformation, and the influence of pit excavation on the adjacent subway tunnel.

This paper analyses the monitoring data of the existing construction stage.

Based on the analyses on the data of field and numerical simulation, the following major findings were obtained: (1) the relationship between the measured maximum wall deflection, δhm, and excavation depth, H, in this study is δhm=0.06%H∼0.27%H, which is quite different compared with the relationship of soft-soil pit δhm=0.02%H∼1.2%H, but closer to the normalized curve of rock-socketed pile δhm=0.01%H∼0.45%H and rock-socketed diaphragm wall δhm=0.031%H∼0.129%H.

(2) The relationship between the maximum settlement of column (δp) and excavation depth (H) is δp=−0.09%∼0.04%H.

The maximum distortion between the diaphragm wall and the column is less than 1/500 of the limit range proposed by Bjerrum.

(3) The impact range caused by excavation is about 3.8 times the maximum excavation depth.

The ground settlement around the foundation pit is groove type, and the maximum settlement point is located at 2.7 times the maximum excavation depth.

(4) The excavation of the foundation pit leads to the maximum vertical settlement of 2 mm and maximum horizontal displacement of 5.2 mm in the subway tunnel; the maximum change of axial force and bending moment are 8.8 kN (the vertical direction) and 6.4 kN·m/m (the horizontal direction), respectively.

American Psychological Association (APA)

Gui, Yue& Zhao, Zhenxing& Qin, Xiaqiang& Wang, Jianfei. 2020. Study on Deformation Law of Deep Foundation Pit with the Top-Down Method and Its Influence on Adjacent Subway Tunnel. Advances in Civil Engineering،Vol. 2020, no. 2020, pp.1-15.
https://search.emarefa.net/detail/BIM-1124095

Modern Language Association (MLA)

Gui, Yue…[et al.]. Study on Deformation Law of Deep Foundation Pit with the Top-Down Method and Its Influence on Adjacent Subway Tunnel. Advances in Civil Engineering No. 2020 (2020), pp.1-15.
https://search.emarefa.net/detail/BIM-1124095

American Medical Association (AMA)

Gui, Yue& Zhao, Zhenxing& Qin, Xiaqiang& Wang, Jianfei. Study on Deformation Law of Deep Foundation Pit with the Top-Down Method and Its Influence on Adjacent Subway Tunnel. Advances in Civil Engineering. 2020. Vol. 2020, no. 2020, pp.1-15.
https://search.emarefa.net/detail/BIM-1124095

Data Type

Journal Articles

Language

English

Notes

Includes bibliographical references

Record ID

BIM-1124095