Numerical investigation of the effect of cross walls in reducing ground settlement induced by deep excavation

2014 ◽  
pp. 173-178
Author(s):  
C Ou ◽  
P Hsieh ◽  
S Chien
Keyword(s):  
Numerical Investigation ◽  
Deep Excavation ◽  
Ground Settlement

scholarly journals Investigation on Dewatering of a Deep Shaft in Strong Permeable Sandy Pebble Strata on the Bank of the Yellow River

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Yuchao Zheng ◽  
Jianyong Lei ◽  
Fei Wang ◽  
Liang Xiang ◽  
Jianfeng Yang ◽  
...  
Keyword(s):  
Permeability Coefficient ◽  
Yellow River ◽  
Pumping Test ◽  
The Yellow River ◽  
Construction Process ◽  
Deep Excavation ◽  
Ground Settlement ◽  
High Permeability ◽  
Reverse Analysis ◽  
Table Versus

This paper reports the dewatering scheme of a deep excavation in sandy pebble strata. The excavation is in high permeability strata and is close to the Yellow River, making the dewatering difficult during construction. At present, few researchers have specially studied the dewatering scheme of deep excavations in strong permeable strata near the water resource. Field pumping test was conducted before the excavation activity, and the permeability coefficient of the strata was obtained by reverse analysis. According to the characteristics of the project, the dewatering scheme of “ waterproof   curtain + base   grouting + pumping ” was proposed. The influence of vertical waterproof curtain and base grouting on dewatering was analyzed by numerical simulation. In the construction process, the field water table and ground settlement were measured. The results show that (1) the groundwater table versus permeability coefficient curve shows three different stages and (2) the dewatering scheme of “ waterproof   curtain + base   grouting + pumping ” is effective for deep excavation in strong permeable strata.

Three-dimensional numerical investigation of multifaced tunneling in water-bearing soft ground

2008 ◽  
Vol 45 (10) ◽  
pp. 1467-1486 ◽  
Author(s):  
Chungsik Yoo ◽  
Sun-Bin Kim
Keyword(s):  
Numerical Investigation ◽  
Three Dimensional ◽  
Element Model ◽  
Soft Ground ◽  
Single Pile ◽  
Ground Settlement ◽  
Axial Loads ◽  
Groundwater Drawdown ◽  
Fully Coupled ◽  
Ground Settlements

This paper presents the results of a numerical investigation of the performance of multifaced tunneling under a pile-supported building in water-bearing soft ground. Special attention was paid to the effect of tunneling and groundwater interaction on the tunneling performance. A fully coupled three-dimensional (3D) stress – pore pressure finite element model was adopted to realistically capture the mechanical and hydrological interaction between the tunneling and groundwater. The results indicate that the groundwater drawdown during tunneling yields a considerably larger settlement-affected zone than for cases with no groundwater drawdown, with a tendency for large portions of ground settlement and groundwater drawdown to be completed before the tunnel passes a monitoring section. Also revealed is that the presence of a building tends to reduce the ground settlements and cause subsurface settlements more or less uniformly with depth. It is shown that the lining deformation, and thus its stresses are not significantly affected by the presence of the building for the multifaced tunneling considered in this study. Axial loads in the piles supporting the building tend to either increase or decrease depending on the pile location relative to the tunnel axis. The patterns of changes in pile axial loads are different from the results of previous studies concerning a single pile.

scholarly journals Deformation Characteristic of a Supported Deep Excavation System: A Case Study in Red Sandstone Stratum

2021 ◽  
Vol 12 (1) ◽  
pp. 129
Author(s):  
Weizheng Liu ◽  
Tianxiong Li ◽  
Jiale Wan
Keyword(s):  
Horizontal Displacement ◽  
Spatial Effects ◽  
Deep Excavation ◽  
Ground Settlement ◽  
Foundation Pit ◽  
Short Side ◽  
Case Record ◽  
Red Sandstone ◽  
Anchor Cable ◽  
Vertical Excavation

A complete case record of a deep foundation pit with pile-anchor retaining structure excavated in red sandstone stratum is presented in this study. The horizontal displacement of pile top, the horizontal displacement at various depths, the axial force of anchor cable, and ground settlement during construction are measured. A three-dimensional numerical model is established to analyze the additional stress and deformation induced by the excavation and the accuracy of the FEM model is verified by comparing with field measured results. Both the measured and numerical simulation results show that the deformation of the pile-anchor supported deep excavation is significantly affected by the spatial effect. The results show that the deformation in the middle of the foundation pit is greater than the pit angle and that the deformation of the long side is greater than that of the short side and gradually decreases from the middle to the pit angle. The deformation and stress in the middle of the long side of the foundation pit are the largest, which is the most unfavorable part. With the increase of vertical excavation depth, the spatial effects tend to increase, and the influence scope of spatial effects is about five times the vertical excavation depth in the red sandstone stratum. The ground settlement outside the pit is mainly distributed in a groove shape, and the maximum settlement occurs about 8.5 m away from the pit edge. Finally, parametric studies of reinforcement parameters indicated that 1.5–2.0 times the initial elastic modulus and cohesive force of soil should be used for reinforcement. It is recommended that the ranges for pile diameter, pile spacing, anchor cable prestressing and inclination angle should be selected as 0.8–1.2 m, 1.4–2.0 m, 100–150 kN, and 10°–20°, respectively.

scholarly journals Prediction of Ground Subsidence During Underground Construction of Metro Line 2, Section 1, Ben Thanh - Tham Luong

2021 ◽  
Vol 1 (2) ◽  
Author(s):  
Nhat Luan VO ◽  
Thi Nu NGUYEN ◽  
Minh Toan DO
Keyword(s):  
Geological Structure ◽  
Surface Settlement ◽  
Ground Subsidence ◽  
Ho Chi Minh City ◽  
Deep Excavation ◽  
Ground Settlement ◽  
Underground Construction ◽  
Structure Characteristics ◽  
Shape And Size ◽  
Element Method

Urban metro line No. 2 from An Suong station to Thu Thiem is one of the six metro lines thatis planned to be built in Ho Chi Minh City (HCMC). The metro line goes through the area in which thestratigraphy consists of many units, distributed from 20-80 m. The hydrogeology mainly has 2 aquifers,namely Holocene, and Pleistocene which affecting the deep excavation. During construction, there willbe some problems that will affect the work on the surface such as settlement, cracking, and damage. Byfinite element method on Plaxis software, the article forecasts the surface settlement during this metroline No.2. The results show that the ground settlement is relatively large in areas with soft groundstructures. The settlement results depend on the geological structure characteristics, hydrogeologicalcharacteristics, and the shape and size of the tunnels.

Deep Excavation Induced Pile Movement in Bangkok Subsoil-A Numerical Investigation

2010 ◽  
Author(s):  
Pornkasem Jongpradist ◽  
Tanapong Rukdeechuai ◽  
Sompote Youwai ◽  
Warat Kongkitkul ◽  
Attasit Sawatpanich ◽  
...  
Keyword(s):  
Numerical Investigation ◽  
Deep Excavation
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