Study on Interaction between Soil and U-Shaped Subway Tunnel in the Environment of Ground Fissures

2011 ◽  
Vol 250-253 ◽  
pp. 2342-2345 ◽  
Author(s):  
Yang Liu ◽  
Kai Ling Li ◽  
Yu Ming Men ◽  
Guang Yuan Weng ◽  
Hong Jia Liu
Keyword(s):  
Hanging Wall ◽  
Interaction Mechanism ◽  
Vertical Displacement ◽  
Soil Mass ◽  
Relative Displacement ◽  
Tunnel Structure ◽  
Subway Tunnel ◽  
Ground Fissure ◽  
Ground Fissures ◽  
Deformation Area

The interaction mechanism, between soil and U-shaped Subway tunnel, is studied by numerical simulation in the environment of ground fissures. The Subway Line 2 through the ground fissures in Xi’an. The analysis results show that the soil mass influenced by the relative displacement and the vertical displacement gradually increases with the relative displacement increasing of ground fissures movement. The deformation area of tunnel lies in the two sides of presupposed ground fissure, and the area enlarge with vertical relative displacement increasing. The tunnel structure damages at the ground fissures when the relative displacement reaches to 100mm. The footwall part is in tension and the hanging wall part is under pressure on the top of tunnel structure at the ground fissure. The footwall part is under pressure and the hanging wall part is in tension on the bottom of tunnel structure at the ground fissure. In the practical projects, the sectional type tunnel should be employed when the Subway tunnel through the ground fissures.

scholarly journals Activity Characteristics and Safety distance of Gaoliying Ground Fissure in Beijing

2019 ◽  
Vol 79 ◽  
pp. 02009
Author(s):  
Haigang Wang ◽  
Tongchun Qin ◽  
Haipeng Guo ◽  
Juyan Zhu ◽  
Yunlong Wang ◽  
...  
Keyword(s):  
Ground Water ◽  
Land Subsidence ◽  
Groundwater Level ◽  
Hanging Wall ◽  
Three Dimensional ◽  
Vertical Direction ◽  
Rapid Decrease ◽  
Ground Fissure ◽  
Ground Fissures ◽  
Safety Distance

In all ground fissures in Beijing, Gaoliying Ground Fissure has characteristics of highly activity, and it cause serious damages on constructoins. With the distribution as well as the development of land subsidence and the change of the groundwater level, a series of work has been conducted to explain the mechanism of the formation of Gaoliying Ground Fissure. For example, field damage investigations and trench observations were used to define the affected distance of ground fissure; three-dimensional deformation was monitored to determine active characteristic of ground fissure. This paper points out that Gaoliying ground fissure is controlled by Huangzhuang-Gaoliying Fault, which mainly moves in the vertical direction. The rapid decrease of the ground water level greatly increases the development of ground fissure. The distance of damaged zones affected by ground fissure in the hanging-wall of the fault reaches 49.5m, and the distance of damaged zones in the footwall of the fault is 17.5 m. A suggested safety distance of type-one and type-two buildings is 100 m. For type-three buildings, the suggested safety distance is 80 m.

Research Advances in the Interaction among Stratum-Ground Fissure-Tunnel under Subway Dynamic Loading

2012 ◽  
Vol 226-228 ◽  
pp. 1513-1516 ◽  
Author(s):  
Li Qun Yuan ◽  
Hong Jia Liu ◽  
Yu Ming Men
Keyword(s):  
Dynamic Loading ◽  
Dynamic Interaction ◽  
Subway Tunnel ◽  
Ground Fissure ◽  
Ground Fissures ◽  
Term Operation ◽  
Geological Disaster ◽  
Under Construction

Ground fissure is a kind of serious geological disaster. There will be more unprecedented challenges during the construction of the urban subway in ground fissures-developed zone. How to ensure the long-term operation safety of the subway crossing ground fissure belts are the first problems for the subway under construction in the cities with ground fissure developed. One of the important problems is that dynamic interaction and disaster effect control among ground fissure-stratum-subway tunnel under subway dynamic loading, which is also the important problem to be solved in the engineering. This problem involves the following three aspects: (a) the determination of subway dynamic loading; (b) the structure dynamic response of subway tunnel; (c) the interaction among stratum-ground fissure-subway tunnel. According to make a comment on these researches, some issues which are necessary to carry out in this field are suggested.

Physical Model Test for the Interaction on Circular Cross-Section Tunnel Crossing Ground Fissure with 60°

2011 ◽  
Vol 261-263 ◽  
pp. 933-937
Author(s):  
Kai Ling Li ◽  
Yang Liu ◽  
Yu Ming Men ◽  
Jing Ping Yan ◽  
Hong Jia Liu
Keyword(s):  
Physical Model ◽  
Cross Section ◽  
Model Test ◽  
Hanging Wall ◽  
Circular Cross Section ◽  
Structural Deformation ◽  
Physical Model Test ◽  
Tunnel Structure ◽  
Ground Fissure ◽  
Longitudinal Strains

Physical model test about the interaction between tunnel structure and soil under circler tunnel crossing the ground fissure belt with 60° was carried out, measuring the longitudinal strains of structure, the relative displacement at the bottom of the tunnel and the surrounding rock pressure. The test results show the deformation on the tunnel structure with circular cross-section is a composition of bending, shearing and twisting. The main deformation in first stage of settlement is bending, but the twisting deformation is more outstanding after the void appears at the bottom of the tunnel. Structural deformation in hanging wall is larger than that of the footwall, whereas structural stress in footwall is larger than that of the hanging wall. The segmentation of lining tunnel structure should be utilized to fit the distortion, bending and shearing in the metro tunnel aslant crossing the ground fissure belt. Twisting action should be considered in the structural design, and the tunnel structure in footwall should be strengthened by using high-performance concrete.

scholarly journals Deformation Activity Analysis of a Ground Fissure Based on Instantaneous Total Energy

Sensors ◽  
2019 ◽  
Vol 19 (11) ◽  
pp. 2607
Author(s):  
Xianglei Liu ◽  
Shan Su ◽  
Jing Ma ◽  
Wanxin Yang
Keyword(s):  
Time Series ◽  
Total Energy ◽  
Hanging Wall ◽  
Vertical Direction ◽  
Activity Analysis ◽  
Ground Fissure ◽  
Ground Fissures ◽  
Mode Decomposition ◽  
Original Time ◽  
Beijing China

This study proposes a novel instantaneous total energy method to perform an activity analysis of ground fissures deformation, which is calculated by integrating the extreme-point symmetric mode decomposition (ESMD) method and kinetic energy based on the time-series displacement acquired by shape acceleration array (SAA) sensors. The proposed method is tested on the Xiwang Road fissure in Beijing, China. First, to fully monitor the hanging wall and footwall of the monitored ground fissure, a 4 m-long SAA in the vertical direction and an 8 m-long SAA in the horizontal direction were embedded in a ground fissure to obtain an accurate time-series displacement with an accuracy of ±1.5 mm/32 m and a displacement acquisition frequency of once an hour. Second, to improve the accuracy of the activity analysis, the ESMD method and Spearman’s rho are applied to perform signal denoising of the original time-series displacement obtained by the SAA sensors. Finally, the instantaneous total energy is obtained to analyze the activity of the monitored ground fissure. The results demonstrate that the proposed method is more reliable to reflect the activity of a monitored ground fissure compared to the time-series displacement.

Model Test of the Impact of Active Ground Fissures on Metro Tunnel

2013 ◽  
Vol 405-408 ◽  
pp. 1334-1339
Author(s):  
Yi Yuan ◽  
Qiang Bing Huang ◽  
Jie Han ◽  
Ming Li Li
Keyword(s):  
Model Test ◽  
Hanging Wall ◽  
Foot Wall ◽  
Test Results ◽  
Soil Pressure ◽  
Ground Fissure ◽  
Ground Fissures ◽  
Tunnel Diameter ◽  
Metro Tunnel ◽  
The Impact

A model test was performed to investigate the impact of active ground fissure on metro tunnel. The test results show that under the action of active ground fissure, the metro tunnel behaviors as a cantilever elastic foundation beam, and the top is in tension and its bottom is in compression. The tensile parts are located in the foot-wall with the range 0.75～2.33D（D is tunnel diameter） distance from active ground fissure and the compressive parts are mainly located in the foot-wall with the range 3D distance from the fissure. When the settlement of hanging wall of ground fissure reaches 1cm（25cm in prototype）, the tunnel bottom appear cavity in the hanging wall and cracks in the foot-wall. With the settlement development of the hanging wall of active ground fissure the vertical soil pressure on the top of tunnel greatly increases and reduces at the bottom of tunnel in the hanging wall.

Analysis of the stress-strain state of a vertical ground electrode system for permafrost soils under pushing loads

2021 ◽  
pp. 77-89
Author(s):  
I. S. Sukhachev ◽  
P. V. Chepur ◽  
A. A. Tarasenko ◽  
A. A. Gruchenkova ◽  
Yuhai Guan
Keyword(s):  
Equivalent Stress ◽  
Side Surface ◽  
Metal Structure ◽  
Vertical Displacement ◽  
Soil Mass ◽  
Electrode System ◽  
Plastic Properties ◽  
Design Scheme ◽  
Permafrost Soils ◽  
Vertical Ground

The article proposes the design, design scheme and model of a vertical ground electrode system with lobe lugs for permafrost soils. The model was implemented using the ANSYS software. In the design scheme, the soil — ground electrode system is taken into account, the elastic-plastic properties of the soil are taken into account by the Drucker — Prager model. When modeling the work of the foundation soils, the Mises strength condition was adopted, according to which the equivalent stress is calculated under the condition of the material hydrostatic compression. The following boundary conditions are accepted: a cylinder-shaped soil mass is rigidly fixed along the lower face and along the side surface of the cylinder. Calculations are made for 5 standard sizes of grounding conductors. Maps of the distribution of stresses in the metal structure of the ground electrode (the rod and petals-emphasis) are received, the movements of the ground electrode in the soil mass are determined. The dependences between the maximum equivalent stresses in the ground electrode lobes and the value of vertical displacement in the ground base are established, as well as the amount of movement of the earthing pad, at which the effective equivalent voltages reach critical values in the area where the paddles are adjacent to the rod.

Identifying Cable Tension Loss and Deck Damage in a Cable-Stayed Bridge Using a Moving Vehicle

2011 ◽  
Vol 133 (2) ◽  
Author(s):  
Shih-Hsun Yin ◽  
Chung-Yu Tang
Keyword(s):  
Computational Study ◽  
Vertical Displacement ◽  
Relative Displacement ◽  
Future Research ◽  
Integration Scheme ◽  
Time Step ◽  
Cable Tension ◽  
Displacement Response ◽  
Cable Stayed Bridge ◽  
Response Vector

This paper presents a computational study on a new method of detecting multiple simultaneous damages in a cable-stayed bridge by use of the analysis of the vertical dynamic response of a vehicle passing the bridge. First, the study uses a finite-element method to simulate the vehicle cable-stayed bridge system. Then, the vertical vibration interaction between the bridge and the vehicle is solved by a time-step integration scheme. In this research, we consider that two kinds of damage including cable tension loss and deck damage may occur simultaneously at different locations. The differences between the vertical displacement responses of a vehicle passing the damaged bridge and the healthy bridge are sampled and called the relative displacement response vector of the vehicle. The proper orthogonal decomposition (POD) is utilized to decompose the relative displacement response vector of the vehicle passing the bridge with unknown multiple damages into an optimal set of basis vectors formed from the ones of the vehicle moving over the known damaged bridges. The associated system parameters variation with the unknown multiple damages can be reconstructed further. Discussions are given concerning the feasibility and limitation of the proposed detection technique as well as directions for future research.

Mutual influence of long-span urban highway tunnel and rail transit construction

2021 ◽  
pp. 1-15
Author(s):  
Honglin Yu ◽  
Shiyang Liu ◽  
Chun Zheng ◽  
Yun Li ◽  
Jie Liu
Keyword(s):  
Mutual Influence ◽  
Vertical Displacement ◽  
Relative Displacement ◽  
Urban Rail Transit ◽  
Rail Transit ◽  
Railway Line ◽  
Long Span ◽  
Highway Tunnel ◽  
Urban Rail ◽  
Secondary Lining

In order to analyze the mutual influence between the long-span highway tunnel and urban rail transit tunnel that is constructed at proximity, this paper established 3D finite element models based on Chongqing Zengjiayan Tunnel and the Metro Railway Line 9 and Line 10 projects to calculate and analyze the secondary lining stress, distribution and change law of deformation of Zengjiayan Tunnel and the Metro Railway Line Tunnel. The results show that: (1) The main risk of the Zengjiayan Tunnel is that the tunnel body might displace in the excavation and the surrounding rock stress could possibly change. The forces undertaken by the main structure of the cross-section are calculated and analyzed based on the shallow buried tunnel. Accordingly, the horizontal and vertical displacement limit and relative displacement meet the relevant specification; (2) Zengjiayan Tunnel over the lobby of Liyuchi Station, a transitional station of Line 9 and Line 10. The main risk is the displacement of the transitional channel in the excavation and changes in the stress on surrounding rocks, but the risk of self-structure excavation and support is under control.

scholarly journals Land Subsidence and Ground Fissures in Beijing Capital International Airport (BCIA): Evidence from Quasi-PS InSAR Analysis

2019 ◽  
Vol 11 (12) ◽  
pp. 1466 ◽  
Author(s):  
Mingliang Gao ◽  
Huili Gong ◽  
Xiaojuan Li ◽  
Beibei Chen ◽  
Chaofan Zhou ◽  
...  
Keyword(s):  
Time Series ◽  
Time Series Analysis ◽  
Land Subsidence ◽  
Deformation Rate ◽  
Normal Operation ◽  
Integrated Analysis ◽  
Ground Fissure ◽  
Ground Fissures ◽  
International Airport ◽  
Series Analysis

Land subsidence is a global environmental geological hazard caused by natural or human activities. The high spatial resolution and continuous time coverage of interferometric synthetic aperture radar (InSAR) time series analysis techniques provide data and a basis for the development of methods for the investigation and evolution mechanism study of regional land subsidence. Beijing, the capital city of China, has suffered from land subsidence for decades since it was first recorded in the 1950s. It was reported that uneven ground subsidence and fractures have seriously affected the normal operation of the Beijing Capital International Airport (BCIA) in recent years before the overhaul of the middle runway in April 2017. In this study, InSAR time series analysis was successfully used to detect the uneven local subsidence and ground fissure activity that has been gradually increasing in BCIA since 2010. A multi-temporal InSAR (MT-InSAR) technique was performed on 63 TerraSAR-X/TanDem-X (TSX/TDX) images acquired between 2010 and 2017, then deformation rate maps and time series for the airport area were generated. Comparisons of deformation rate and displacement time series from InSAR and ground-leveling were carried out in order to evaluate the accuracy of the InSAR-derived measurements. After an integrated analysis of the distribution characteristics of land subsidence, previous research results, and geological data was carried out, we found and located an active ground fissure. Then main cause of the ground fissures was preliminarily discussed. Finally, it can be conducted that InSAR technology can be used to identify and monitor geological processes, such as land subsidence and ground fissure activities, and can provide a scientific approach to better explore and study the cause and formation mechanism of regional subsidence and ground fissures.

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