The Monitoring and Analysis of Surface Subsidence of Soft Soil Rock Large Section of Subway Tunnel Shield Construction

2013 ◽  
Vol 848 ◽  
pp. 78-82
Author(s):  
Jin Kui Li ◽  
Bing Wei Yan ◽  
Yong Jian Shi
Keyword(s):  
Surface Deformation ◽  
Soft Soil ◽  
Reference Value ◽  
Lateral Position ◽  
Surface Subsidence ◽  
Subway Tunnel ◽  
Tunnel Excavation ◽  
Working Face ◽  
Shield Machine ◽  
Tunnel Shield

In this paper use the shield construction of Dalian subway 202 bid section as an example, carried out the monitoring measurement of surface subsidence and crown surface subsidence during the shield construction, detailed analysis the monitoring data, explored the characteristics and distribution of surrounding rock and surface deformation of large cross section shield construction. Construction transverse deformation has a relationship with lateral position and the tunnel excavation length. The closer from shield machine working face, the closer to the center line of the tunnel, the greater impact is. The research results have reference value for the future similar engineering design and construction.

scholarly journals Surface deformation evolution in the Pearl River Delta between 2006 and 2011 derived from the ALOS1/PALSAR images

2020 ◽  
Vol 72 (1) ◽  
Author(s):  
Genger Li ◽  
Guangcai Feng ◽  
Zhiqiang Xiong ◽  
Qi Liu ◽  
Rongan Xie ◽  
...  
Keyword(s):  
Land Subsidence ◽  
Pearl River Delta ◽  
Surface Deformation ◽  
Soft Soil ◽  
Soil Layer ◽  
Intrinsic Factor ◽  
Surface Subsidence ◽  
River Delta ◽  
Pearl River ◽  
Human Interference

AbstractThis study monitors the land subsidence of the whole Pearl River Delta (PRD) (area: ~ 40,000 km2) in China using the ALOS1/PALSAR data (2006–2011) through the SBAS-InSAR method. We also analyze the relationship between the subsidence and the coastline change, river distribution, geological structure as well as the local terrain. The results show that (1) the land subsidence with the average velocity of 50 mm/year occurred in the low elevation area in the front part of the delta and the coastal area, and the area of the regions subsiding faster than 30 mm/year between 2006 and 2011 is larger than 122 km2; (2) the subsidence order and area estimated in this study are both much larger than that measured in previous studies; (3) the areas along rivers suffered from surface subsidence, due to the thick soft soil layer and frequent human interference; (4) the geological evolution is the intrinsic factor of the surface subsidence in the PRD, but human interference (reclamation, ground water extraction and urban construction) extends the subsiding area and increases the subsiding rate.

scholarly journals Surface Deformation Evolution in the Pearl River Delta between 2006 and 2011 derived from the ALOS1/PALSAR images

2020 ◽  
Author(s):  
Genger Li ◽  
Guangcai Feng ◽  
Zhiqiang Xiong ◽  
Qi Liu ◽  
Rongan Xie ◽  
...  
Keyword(s):  
Land Subsidence ◽  
Pearl River Delta ◽  
Surface Deformation ◽  
Soft Soil ◽  
Soil Layer ◽  
Intrinsic Factor ◽  
Surface Subsidence ◽  
River Delta ◽  
Pearl River ◽  
Human Interference

Abstract This study monitors the land subsidence of the whole Pearl River Delta (PRD) (area: ~40,000 km2) in China using the ALOS1/PALSAR data (2006-2011) through the SBAS-InSAR method. We also analyze the relationship between the subsidence and the coastline change, river distribution, geological structure as well as the local terrain. The results show that (1) the land subsidence with the average velocity of 50 mm/year occurred in the low elevation area in the front part of the delta and the coastal area, and the area of the regions subsiding fast than 30 mm/year between 2006 and 2011 is larger than 122 km2; (2) the subsidence order and area estimated in this study are both much larger than that measured in previous studies; (3) the areas along rivers suffered from surface subsidence, due to the thick soft soil layer and frequent human interference; (4) the geological evolution is the intrinsic factor of the surface subsidence in the PRD, but human interference (reclamation, ground water extraction and urban construction) extends the subsiding area and increases the subsiding rate.

Analysis of the Ground Surface Settlement of Metro Tunnel by Using Peck Formula

2014 ◽  
Vol 1065-1069 ◽  
pp. 414-420
Author(s):  
Xiong Fei Yang ◽  
Hong Yuan ◽  
Jia Yu Wu ◽  
Hou Mei Zhang
Keyword(s):  
Surface Deformation ◽  
Ground Surface ◽  
Surface Subsidence ◽  
Central Point ◽  
Surface Settlement ◽  
Point Method ◽  
Linear Regression Method ◽  
Tunnel Excavation ◽  
Ground Surface Settlement ◽  
Ground Surface Subsidence

Based on the peck formula, this paper has analyzed measured data of ground surface subsidence, and get the regression curve of ground surface subsidence. Expression for degree of reliability of the maximum ground surface settlement is derived analytically by using central-point method. On the basis of a certain section of tunnel of Guangzhou subway constructed by mining excavation method, linear regression method can be effectively fitting the ground surface deformation data due to tunnel excavation. The central-point method provides a new way for reliability analysis of the ground surface settlement of shield construction.

scholarly journals Study on Deformation Law of Subway Construction under Passing Existing Line in Short Distance

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Cong-Shuang Luo ◽  
Yi-Hong Cheng ◽  
Zhe Bai ◽  
Tong Shen ◽  
Xu-Yang Wu ◽  
...  
Keyword(s):  
Large Scale ◽  
Subway Tunnel ◽  
Deformation Law ◽  
Space Projects ◽  
Development And Utilization ◽  
Grouting Reinforcement ◽  
Track Surface ◽  
Shield Machine ◽  
Safety And Stability ◽  
Tunnel Shield

With the large-scale development and utilization of underground space projects, the subway-led Rail Transit Project is developing vigorously, and the safety and stability of subway under passing existing projects have become a key issue for the future. In this paper, the deformation law of subway tunnel under the existing track is studied by using the method of ROCSCIENCE software and field measurement, which is based on the construction of a new double-tunnel shield-driven subway tunnel under the existing city of pile rapid track project. In the crossing area, the distance between the top of the tunnel and the pile foundation is 6.2 m and the distance between the tunnel and the existing track surface is 19.6 m. It is required that the settlement of track caused by the new tunnel construction should not exceed 2 mm. The results show that the settlement of the existing track is greatly influenced by the new tunnel without reinforcement and grouting, and the maximum settlement is more than 9.92 mm. The settlement of the existing track can be controlled to 1.93 mm by adjusting the construction parameters of the shield machine and grouting reinforcement at different stages during construction.

Finite Element Analysis of the Construction of the Subway Tunnel Test Section below through the Railway Bridges

2012 ◽  
Vol 170-173 ◽  
pp. 1648-1651
Author(s):  
Run Ke Huo ◽  
Pei Yuan Lun ◽  
Yong Zhen Yao ◽  
Jie Li
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Structure Stability ◽  
Subway Tunnel ◽  
Element Analysis ◽  
Tunnel Excavation ◽  
Railway Bridges ◽  
Working Face ◽  
Harbin City ◽  
Primary Support

During the construction of city subway, it often needs to cross under the existing buildings, which will have some influence on these buildings. The article, taking the engineering of subway tunnel in Harbin city for example, uses finite element analysis software to simulate the dynamic excavation of the tunnel, and combines with the measured data of actual monitoring, analyzes the primary support structure stability in the process of tunnel excavation. Finally it draws the conclusion that the stress and displacement near the working face change greatly, the springback displacement of tunnel bottom is big, fracture surface near the entrance of the hole tends to be stable with the excavate of the working face.

Effect of Shield Tunneling on the Nearby Pile Foundations

2011 ◽  
Vol 250-253 ◽  
pp. 3559-3563
Author(s):  
Ya Jun Wu ◽  
Dao Min Zou ◽  
Gang Li
Keyword(s):  
Concrete Strength ◽  
Reference Value ◽  
Negative Influence ◽  
Pile Foundations ◽  
Shield Tunneling ◽  
Pile Shaft ◽  
Practical Engineering ◽  
Shield Machine ◽  
Two Sides ◽  
Tunnel Shield

Shield tunneling may have negative influence on the nearby facilities. Especially, it will cause the additional stresses and moments along the pile shaft. If the stresses and deformation of a pile exceed the allowable values, that will affect its normal use and even result in its damage. Therefore, base on a practical engineering in Shanghai, some factors such as the distances between a pile and a tunnel, the concrete strength of a pile are investigated using finite diffrence method. The results show: the degree of disturbing soil in two sides of the tunnel is greater than that of soil in front of the tunnel; shield tunneling has a strong effect on a pile within a distance of 3m between the pile and the shield machine; however, if the distance is in excess of 3m, the effect is not too strong. Furthermore, the grade concrete strength of a pile has little effect on the pile behavior. This conclusion has some reference value to the actual project.

Prediction of long-term settlements of subway tunnel in the soft soil area

2014 ◽  
Vol 74 (2) ◽  
pp. 1007-1020 ◽  
Author(s):  
Zhen-Dong Cui ◽  
Shi-Xi Ren
Keyword(s):  
Soft Soil ◽  
Subway Tunnel ◽  
Soft Soil Area ◽  
Soil Area

The Stability Control of Soft Soil Foundations of Urban Roads According to the Surface Subsidence Monitoring Data

2013 ◽  
Vol 859 ◽  
pp. 222-227
Author(s):  
Hong Jun Liu ◽  
Jin Hua Tan ◽  
Xue Wen Su ◽  
Hao Wu
Keyword(s):  
Soft Soil ◽  
Stability Control ◽  
Surface Subsidence ◽  
Monitoring Data ◽  
Research Results ◽  
The Road ◽  
Future Design ◽  
Left And Right ◽  
Soil Foundation ◽  
The Stability

Two typical monitoring sections are selected for obtaining the change law of the surface subsidence and the settlement after construction of soft soil foundations, and determining the reasonable unloading time. The research results show that the surface settlement rate is large during the filling stage, the rate decreases after the loading and gradually stabilized. The embankment midline settlement is larger than the settlement of the road shoulder which is concluded from the fact that the subsidence of the middle settlement plate is larger than those of the left and right plate. The surface subsidence rate is less than 5mm per month during the two month before unloading according to the data in the tables. The settlement after construction presumed from the middle plate is more significantly larger than that of left and right sides, hence, as the unloading basis of preloading drainage method in soft soil foundation treatment the settlement after construction which is calculated from the midline monitoring data of the road is appropriate. After 6 months the calculated post-construction settlements of the two sections are in the scope of the design requirement since they decrease with preloading time. The reliable basis is provided for the future design and construction of soft foundation in this area through the research results.

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