Influencing factors and protection technologies of underground diaphragm wall and deep foundation pit construction on metro station

This article mainly expounds the importance of in-situ monitoring on the construction process of deep foundation pit. Taking the deep foundation pit of some Shenyang metro station for example, the deformation features of the supporting structure and the internal and external of foundation pit is analyzed, according to the monitoring data of the fender pile displacement during the excavation of deep foundation pit. The conclusion is obtained that the timely and accurate in-situ monitoring information is necessary to guaranteeing construction safety. We should pay more attention to the excavation speed and exert the interior support timely during the excavation of foundation pit to avoid large deformation and danger. The analytical results of monitoring data shows that the whole stage of foundation pit excavation is stable and the fender pile with internal supports can guarantee the stability of foundation pit.

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Research on Deformation Law of Deep Excavation Supporting Structures in Beijing Metro Station

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.243-249.2338 ◽

2011 ◽

Vol 243-249 ◽

pp. 2338-2344

Author(s):

Qing Yuan Li ◽

Yang Wang

Keyword(s):

Horizontal Displacement ◽

Internal Force ◽

In Situ Monitoring ◽

Deep Excavation ◽

Deep Foundation ◽

Foundation Pit ◽

Metro Station ◽

Deep Foundation Pit ◽

Deformation Law

Taking deep excavation engineering in North Region of Senlin Park Station of Beijing Olympic Subway branch as engineering background, deformation law of enclosure structure of deep excavation are studied by the in-situ monitoring means .It shows that the maximum horizontal displacement of retaining pile is closely related with excavation depth and time. When the deep foundation pit is excavated to a certain depth, and steel brace hasn’t been erected, horizontal displacement of the pile tops is maximum. The location of the maximum horizontal displacement shifts down with foundation pit excavation and steel brace erection. With steel brace application, steel axis force decrease, so steel brace can effectively control horizontal displacements of retaining pile and internal force of steel in the pile. In addition, temperature has a certain effect to axis force of steel brace.

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Deformation Law of the Diaphragm Wall during Deep Foundation Pit Construction on Lake and Sea Soft Soil in the Yangtze River Delta

Advances in Civil Engineering ◽

10.1155/2021/6682921 ◽

2021 ◽

Vol 2021 ◽

pp. 1-11

Author(s):

Yuan Mei ◽

Dongbo Zhou ◽

Xueyan Wang ◽

Liangjie Zhao ◽

Jinxin Shen ◽

...

Keyword(s):

Soft Soil ◽

Yangtze River Delta ◽

Diaphragm Wall ◽

Lateral Deformation ◽

Deep Foundation ◽

Foundation Pit ◽

Deep Foundation Pit ◽

Deformation Law ◽

Wall Deformation ◽

Subway Stations

So far, there have been a large number of diaphragm walls in the Yangtze River Delta as engineering examples of deep foundation pit maintenance structures in subway stations, but there is a lack of systematic research and summary on the deformation characteristics of ground connecting walls. This study aimed to clarify the deformation law of the diaphragm wall during the excavation of a deep foundation pit in a soft soil region. Based on the monitoring data of the diaphragm wall of the deep foundation pit of the Hangzhou metro station, the monitoring data of the deep foundation pits of 15 subway stations in Shanghai and Ningbo cities around Hangzhou were considered. Grouping and classification methods were used to analyze the similarities and differences in the deformation characteristics of the diaphragm wall in the three regions. The results indicate the following: the maximum lateral deformation of the diaphragm wall in Hangzhou increases linearly with the relative depth of the maximum lateral deformation. The maximum lateral deformation of the foundation pit in Hangzhou is 0.072% H∼0.459% H, with a mean of 0.173% H. The wall deformation in Hangzhou varies significantly with the depth of the foundation pit, but the influence of the depth of the foundation pit on the wall deformation is considerably less than that in Shanghai and Ningbo. The corresponding position of the maximum lateral deformation in the excavation depth increases linearly with the excavation depth of the foundation pit, and the corresponding position of the lateral deformation of the diaphragm wall in Shanghai is more affected by the excavation depth of the foundation pit. The lateral deformation of the diaphragm wall increases rapidly in the range of 0 H–0.5 H, and the maximum lateral deformation occurs at 0.5 H–1.1 H.

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Finite-Difference Numerical Simulation of Dewatering System in a Large Deep Foundation Pit at Taunsa Barrage, Pakistan

Sustainability ◽

10.3390/su11030694 ◽

2019 ◽

Vol 11 (3) ◽

pp. 694 ◽

Cited By ~ 1

Author(s):

Ijaz Ahmad ◽

Muhammad Tayyab ◽

Muhammad Zaman ◽

Muhammad Anjum ◽

Xiaohua Dong

Keyword(s):

Hydraulic Conductivity ◽

Finite Difference ◽

Three Dimensional ◽

Rehabilitation Program ◽

Diaphragm Wall ◽

Deep Foundation ◽

Foundation Pit ◽

Deep Foundation Pit ◽

Constant Head ◽

Design Depth

This study investigates a large deep foundation pit of a hydraulic structure rehabilitation program across the Indus river, in the Punjab province of Pakistan. The total area of the construction site was 195,040 m2. Two methods, constant head permeability test and Kozeny–Carman equation, were used to determine the hydraulic conductivity of riverbed strata, and numerical simulations using the three-dimensional finite-difference method were carried out. The simulations first used hydraulic conductivity parameters obtained by laboratory tests, which were revised during model calibration. Subsequently, the calibrated model was simulated by different aquifer hydraulic conductivity values to analyze its impact on the dewatering system. The hydraulic barrier function of an underground diaphragm wall was evaluated at five different depths: 0, 3, 6, 9, and 18 m below the riverbed level. The model results indicated that the aquifer drawdown decreases with the increase in depth of the underground diaphragm wall. An optimal design depth for the design of the dewatering system may be attained when it increases to 9 m below the riverbed level.

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Study on soil reinforcement param in deep foundation pit of marshland metro station

Heliyon ◽

10.1016/j.heliyon.2019.e02836 ◽

2019 ◽

Vol 5 (11) ◽

pp. e02836 ◽

Cited By ~ 1

Author(s):

Wei Wang ◽

Zhao Han ◽

Jun Deng ◽

Xinyuan Zhang ◽

Yanfei Zhang

Keyword(s):

Soil Reinforcement ◽

Deep Foundation ◽

Foundation Pit ◽

Metro Station ◽

Deep Foundation Pit

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Monitoring of Deformation Laws of Deep Excavation in Metro Station

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.99-100.1141 ◽

2011 ◽

Vol 99-100 ◽

pp. 1141-1145

Author(s):

Qing Yuan Li

Keyword(s):

Monitoring Program ◽

Deep Foundation ◽

Foundation Pit ◽

Basic Principles ◽

Metro Station ◽

Deep Foundation Pit ◽

Site Monitoring ◽

Information Construction ◽

Engineering Information ◽

Engineering Environment

Combined with the Engineering environment and the requirements of construction of the deep foundation of metro station of South Gate in Xi'an, and in accordance with the basic methods and the basic principles of the monitoring of the construction of deep foundation, it gives a monitoring program of the deformation of the deep foundation pit and researches on in-site monitoring for the deformation of deep foundation, to ensure the safety of metro station construction. At the same time, it focuses on an analysis of the horizontal deformation of the retaining piles and the axial force of steel support, to provide a reference for the similar engineering information construction in the future.

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