scholarly journals Bridge Responses Induced by Adjacent Subway Station Construction Using Shallow Tunneling Method

2018 ◽  
Vol 2018 ◽  
pp. 1-16 ◽  
Author(s):  
Jie Su ◽  
Qian Fang ◽  
Dingli Zhang ◽  
Xiaokai Niu ◽  
Xiang Liu ◽  
...  
Keyword(s):  
Prestressed Concrete ◽  
Pile Foundation ◽  
Ground Surface ◽  
Deformation Monitoring ◽  
Subway Station ◽  
Horizontal Distance ◽  
Protection Measure ◽  
Tunneling Method ◽  
Bridge Responses ◽  
Reinforcement Measures

This paper presents a case of subway station construction under an existing prestressed concrete bridge with a three-span continuous beam located at the intersection of the 3rd Ring Road, Beijing. The Huayuan Subway Station of line 6, constructed crossing between #7 and the #8 piers of the bridge by the shallow tunneling method, is approximately perpendicular to the existing Huayuan Bridge. The minimum horizontal distance between the pile foundation and the subway station is only 0.08 m. The “Pile-Beam-Arc” construction sequence was used to ensure the safety of both the subway station and the bridge. Moreover, a series of reinforcement measures were adopted to safeguard the project, including deep grouting reinforcement surrounding the pile foundation from ground surface, temporary inverted arch in the middle of No. 5 drift, and the lateral steel support. Even though some cracks were observed on the bridge deck surface by the on-site deformation monitoring, the results were still within the proposed control standard. To prevent the further development of the cracks, jacking protection measure and bonded steel constructed under the box girder were performed. The related measures proposed in this research can provide useful references for future similar projects.

Mechanical Analysis of Enclosure Pile under Different Constraints

2011 ◽  
Vol 90-93 ◽  
pp. 485-489
Author(s):  
Li Guo ◽  
Peng Li He ◽  
Guang Jun Zhang
Keyword(s):  
Mechanical Analysis ◽  
Subway Station ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Deep Foundation Pit ◽  
Retaining Structure ◽  
Cantilever Structure ◽  
Reinforcement Measures

The enclosure pile is extensively used as retaining structure in the foundation pit excavation. And it is always combined with other reinforcement measures. So it is unreasonable to a certain degree that the enclosure pile is analyzed as cantilever structure. Taken the deep foundation pit of a subway station in Hefei for instance, the effect of other reinforcement measures on restrained conditions of enclosure piles in the paper was taken into account. And the behavior of enclosure pile under various restrained conditions was analyzed. Based on that, some helpful suggestions for practical retaining structure of foundation pit were put forward.

Results of an Instrumented Static Loading Test and Its Application to Design Compilation of an International Survey

2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Bengt Fellenius
Keyword(s):  
Prestressed Concrete ◽  
Static Loading ◽  
Ground Surface ◽  
Loading Test ◽  
Text Book ◽  
Ground Surface Settlement ◽  
Static Loading Test ◽  
Residual Force ◽  
Available Information ◽  
Piled Foundations

Results of a static loading test were used together with soil exploration records in a survey comprising analysis of the test records and estimating settlement of piled foundation to support a pipe rack. The test pile was a strain-gage instrumented, 400-mm diameter, precast, prestressed concrete pile driven into a clay and silt deposit to 25 m embedment. Two main issues were expected to be addressed by the survey participants: First, realization that the strain records were affected by presence of residual force in the pile and, second, calculation of the settlement of the piled foundation expected from the foundation load. A total of 52 submissions were received from 20 different countries. Only 12 of the submissions realized the presence of residual force. Most submissions reported a calculated settlement of the piled foundations ranging from 10 mm through 50 mm; however, 11 reported values between 60 and 200 mm. Surprisingly, only 20 submissions reported ground surface settlement close to the 200-mm value resulting from text-book analysis based on the available information. The subsequent construction of the piled foundations coincided with placing a fill across the site and lowering of the groundwater table, thus, causing a general subsidence.

Research of the Key Reinforcement Technology Based on Miaoziping Bridge of Du Wen Expressway after the Wenchuan Earthquake

2011 ◽  
Vol 243-249 ◽  
pp. 1377-1382
Author(s):  
Xian Bin Huang ◽  
Jia Chen ◽  
Zhan Yuan Zhu ◽  
Wen Hai En ◽  
Jian Liang
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Flaw Detection ◽  
Ground Surface ◽  
Bridge Strengthening ◽  
Pressure Water ◽  
High Pressure Water Jet ◽  
Reinforcement Measures ◽  
Reinforcement Design ◽  
Good Workability

The height from the bridge deck of 5th main pier to ground surface is about115m, and the depth from the top surface of pier cap to water surface is 65m. Reinforcement measures such as flaw detection by frogman, hole plugged, steel caisson placing, steel caisson modeling, high performance concrete seal cracks perimeter. Reinforcement show that, the effect of high-pressure water jet roughening and hole plugged is well; the steel caisson which weighs about 400t sinking stablely and reaching the intended design location; great liquidity, high performance concrete has good workability , 28d strength is above the design and specification demands, bridge static and dynamic tests meeting the design requirements. The research is important for bridge strengthening, and provides reference for the reinforcement design and construction of the same type bridge.

scholarly journals Deformation Monitoring of Earth Fissure Hazards Using Terrestrial Laser Scanning

Sensors ◽  
2019 ◽  
Vol 19 (6) ◽  
pp. 1463 ◽  
Author(s):  
Yunfeng Ge ◽  
Huiming Tang ◽  
Xulong Gong ◽  
Binbin Zhao ◽  
Yi Lu ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Ground Surface ◽  
Terrestrial Laser Scanning ◽  
Point Clouds ◽  
Vertical Displacement ◽  
Deformation Monitoring ◽  
Earth Fissure ◽  
Displacement Analysis ◽  
Remote Sensing Technique ◽  
Noise Data

Deformation monitoring is a powerful tool to understand the formation mechanism of earth fissure hazards, enabling the engineering and planning efforts to be more effective. To assess the evolution characteristics of the Yangshuli earth fissure hazard more completely, terrestrial laser scanning (TLS), a remote sensing technique which is regarded as one of the most promising surveying technologies in geohazard monitoring, was employed to detect the changes to ground surfaces and buildings in small- and large-scales, respectively. Time-series of high-density point clouds were collected through 5 sequential scans from 2014 to 2017 and then pre-processing was performed to filter the noise data of point clouds. A tiny deformation was observed on both the scarp and the walls, based on the local displacement analysis. The relative height differences between the two sides of the scarp increase slowly from 0.169 m to 0.178 m, while no obvious inclining (the maximum tilt reaches just to 0.0023) happens on the two walls, based on tilt measurement. Meanwhile, global displacement analysis indicates that the overall settlement slowly increases for the ground surface, but the regions in the left side of scarp are characterized by a relatively larger vertical displacement than the right. Furthermore, the comparisons of monitoring results on the same measuring line are discussed in this study and TLS monitoring results have an acceptable consistency with the global positioning system (GPS) measurements. The case study shows that the TLS technique can provide an adequate solution in deformation monitoring of earth fissure hazards, with high effectiveness and applicability.

Study on Structural Design and Driving Process of a Subway Station with Large Transection by Tunneling Method

2013 ◽  
Vol 353-356 ◽  
pp. 1325-1328 ◽  
Author(s):  
Xiao Jun Zhou ◽  
Chang Yu Yang
Keyword(s):  
Rock Mass ◽  
Structural Design ◽  
Subway Station ◽  
Great Success ◽  
Construction Process ◽  
Tunneling Method ◽  
Geological Conditions ◽  
Cut Method ◽  
Transfer Station ◽  
Composite Lining

Structural design and construction process for a subway station consists of two tunnels with large transection are discussed according to its function and geological conditions of rock mass in this paper. A composite lining is designed to support surrounding rock, and partial bench cut method, side drift method are utilized to build the special subway transfer station in rock mass. The practice of the designed scenario proves to be a great success and attains the safe construction of the station by tunneling method.

Optimization Analysis of Different Excavation Offsets in Railway Pilot Tunnel by CRD Method

2014 ◽  
Vol 505-506 ◽  
pp. 134-138
Author(s):  
Chun Kui Li
Keyword(s):  
Production Efficiency ◽  
Ground Surface ◽  
Simulation Method ◽  
Subway Station ◽  
Optimization Analysis ◽  
Tunnel Excavation ◽  
Construction Model ◽  
Surface Settlements ◽  
Stress Variations ◽  
Optimal Construction

This paper focuses on the construction of 10 railway pilot tunnels by CRD method in Jiefang Road subway station in Changchun. To achieve the optimal construction offsets during the pilot tunnel excavation, reduce the impacts of group cavern effect, and maximize the production efficiency, the construction model of railway pilot tunnel in subway station was created by the finite difference software Flac3D. The author used the numerical simulation method to analyze the ground surface settlements and the stress variations with three different construction offsets. Then the optimal construction offset was obtained. It could provide a theoretical guidance to the construction of a similar project.

scholarly journals Numerical Simulation of Deep Foundation Pit Construction under Complex Site Conditions

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Huifen Liu ◽  
Kezeng Li ◽  
Jianqiang Wang ◽  
Chunxiang Cheng
Keyword(s):  
Numerical Simulation ◽  
Ground Surface ◽  
Reference Value ◽  
Horizontal Displacement ◽  
Deformation Monitoring ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Deep Foundation Pit ◽  
Ground Surface Settlement ◽  
Stress And Deformation

Based on the deep foundation pit project of Laoguancun station of Wuhan rail transit line 16 and according to the engineering characteristics of the construction conditions and the site surrounding the environment, the method of combining field monitoring and finite element numerical simulation is adopted to analyze the law of stress and deformation of the deep foundation pit during excavation and support construction; it includes the horizontal displacement of the underground diaphragm wall, supporting axial force, and the ground surface settlement, which can be compared with measured data. Finally, some suggestions for monitoring and construction of the deep foundation pit in the subway station have been put forward and have certain reference value and practical guiding significance for the design and construction of similar engineering projects. The deformation monitoring of the retaining structure at the middle of the long side of the foundation pit should be strengthened during the construction process.

The Experimental and Theoretical Research on Creep Effect of Large Prestressed Concrete Box Girder

2014 ◽  
Vol 501-504 ◽  
pp. 1199-1203 ◽  
Author(s):  
Ji Xin Yang ◽  
Pei Liu ◽  
Ming Chao Yang
Keyword(s):  
Influencing Factors ◽  
Prestressed Concrete ◽  
Complex Structure ◽  
Internal Force ◽  
Deformation Monitoring ◽  
Theoretical Research ◽  
Box Girder ◽  
Concrete Creep ◽  
Finite Element Software ◽  
Creep Effect

The concrete creep effect is a peculiar phenomenon of concrete material, it has a significant effect on the deformation and internal force redistribution of concrete member, besides, it may cause the loss of prestress , it may have serious consequences especially on complex structure such as long-span bridges. So it must be considered in bridge design and construction. Based on the subject of CYSG deformation monitoring and 32m precast PC simply supported box girder, the method of creep test has been researched and determined in this paper firstly, then the laws of the development of the creep has been summarized, and the influencing factors of concrete creep has been concluded. Using the finite element software ANSYS and the APDL language, theoretical analysis of creep has been carried on in this paper. In conclusion, This paper analyzed the influencing factors of concrete creep and provided the basis for long-term deformation control of creep by comparing the theoretical results with the experimental data.

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