Numerical Simulation of Shield Tunnel Crossing Masonry Structure Building with Various Degrees

2011 ◽  
Vol 368-373 ◽  
pp. 889-893 ◽  
Author(s):  
Gang Wei
Keyword(s):  
Shear Strain ◽  
Shield Tunnel ◽  
Masonry Building ◽  
Strip Foundation ◽  
Maximum Shear Strain ◽  
Structure Building ◽  
Before And After ◽  
Stress And Deformation ◽  
Shield Machine ◽  
Central Base

Considering the interaction of building-soil-tunnel, the strip foundation masonry building vertical crossed by shield tunnel was simulated by 3D MIDAS/GTS software, and the stress and deformation of building before and after shield machine through the building were analyzed. The results showed that: the deformation and the force are different with different angles through the building; with the angle increases, the central base settlement slightly increased; the maximum overall differential settlement reached at 45 degrees; the maximum shear strain is reached when the machine is completely through the building; with the increase of crossed degree from 22.5 degrees, 45 degrees, 67.5 degrees to 90 degrees, the maximum shear strain of wall increases; the plastic zone of wall is mainly at the top cross position in the wall.

Impact of Double-O-Tube Shield Tunnel Construction on Independent Foundation Frame Building

2011 ◽  
Vol 243-249 ◽  
pp. 3370-3375 ◽  
Author(s):  
Gang Wei ◽  
Jie Hong ◽  
Zhao Lin ◽  
Xin Jiang Wei
Keyword(s):  
Shear Strain ◽  
Principal Stress ◽  
Horizontal Displacement ◽  
Shield Tunnel ◽  
Tunnel Construction ◽  
Shield Tunneling ◽  
Maximum Shear Strain ◽  
Frame Building ◽  
Security Value ◽  
The Impact

Due to its better advantages, Double-O-Tube(DOT) shield has been widely applied in shield tunnel construction. But the impact caused by shield tunnel construction on buildings hasn’t been taken seriously. Considering the interaction of building-soil-tunnel, the independent foundation frame building vertical crossed by DOT shield tunnel was simulated by 3D MIDAS/GTS software, and the impact of construction on the building was analyzed. The results show that: during the passage of the shield tunneling through the building, the settlement of the building increased. The settlement was stable and had a little rebound when shield machine already passed the building. The building’s longitudinal displacement was great larger than lateral horizontal displacement. With the increase of driving distance, the first principal stress P1 and maximum shear strain MSmax increased and then were stable. With the increase of L, the first principal stress P1 and maximum shear strain MSmax tended to gradually reduce the security value, and the maximum differential settlement between columns increased first and then decreased. Finally, the safety of the building was assessed comprehensively.

scholarly journals Influence of Water Inrush from Excavation Surface on the Stress and Deformation of Tunnel-Forming Structure at the Launching-Arrival Stage of Subway Shield

2019 ◽  
Vol 2019 ◽  
pp. 1-20
Author(s):  
Shusheng Lv ◽  
Wen Liu ◽  
Shihong Zhai ◽  
Peishuai Chen
Keyword(s):  
Simulation Analysis ◽  
Coupling Effect ◽  
Water Inrush ◽  
Ground Surface ◽  
Reinforced Soil ◽  
Soil Reinforcement ◽  
Shield Tunnel ◽  
Deformation Properties ◽  
Stress And Deformation ◽  
Shield Machine

The launching-arrival stage of the shield is the most dangerous construction stage in subway construction. During the conversion process of the soil and air medium in the shield machine, water inrush at the excavation surface often occurs because of the effect of groundwater. Previous research has focused on the overall stress and deformation of existing tunnels caused by water inrush from the excavation face of the shield machine excavation stage. However, the stress and deformation states of the segments and anchors at different assembly locations of the tunnel, as well as the interaction between the soil reinforcement region and the segments and anchors in the launching-arrival stage have not been considered in previous studies. In this study, the inrush model of the launching-arrival stage of the subway shield was established by utilizing the equivalent refinement modeling technology and ABAQUS simulation analysis with consideration of the fluid-solid coupling effect of water and soil to study the influences of different water head differences on the mechanical and deformation properties of segments and anchors in shield construction under the conditions of water inrush on the excavation surface. The results showed that the water inflow from the tunnel excavation surface caused significant surface subsidence at the tunnel portal, vertical convergence at the cross section of the shield tunnel, and significant increases in the axial and shear forces on the bolt. In addition, based on the existing subway regulation, combined with the simulation results of soil reinforcement measures at different depths, the emergency control criterion for controlling water inrush on the excavation surface was established by using the depth of soil reinforcement. The minimum depth of the reinforced soil from the ground surface at 15 m is recommended to ensure construction safety of the subway shield at the launching-arrival stage.

Analysis of Dalian Subway Tunnel Shield Construction Impact with Engineering Materials and Engineering Mechanics on Existing Bridge Pier

2013 ◽  
Vol 848 ◽  
pp. 96-99
Author(s):  
Jin Kui Li ◽  
Qing Hao Hou ◽  
Wen Jing Liang
Keyword(s):  
Bridge Pier ◽  
Shield Tunnel ◽  
Subway Tunnel ◽  
Construction Monitoring ◽  
Measuring Point ◽  
Close Proximity ◽  
Before And After ◽  
Total Settlement ◽  
Shield Machine ◽  
Time Away

In the 202 section of subway shield Dalian interval in close proximity to existing bridge as the basis, the surface settlement and bridge pier settlement observation station are established. By the 62 day of the crossing construction monitoring, the monitoring data are analyzed in detail. When surface subsidence induced by shield tunnel construction, above the measuring point start speed is faster than settling startup speed measuring points on both sides, about 2-2.5 times, subsidence range higher about 8 to 10 m ahead of time. Away from the pier side first started, and start faster than the side near the pier ,is about 1.2 times , settlement of shield construction are mainly concentrated in the distance before and after the excavation of shield machine 10 m, accounting for 80.72%-81.6% of the total settlement . At highest risk for shield construction area, we should strengthen monitoring and make contingency plans in a timely manner.

Impact of Double-O-Tube Shield Tunnel Construction on Grillage Beams Foundation Frame Building

2011 ◽  
Vol 71-78 ◽  
pp. 32-36 ◽  
Author(s):  
Xin Jiang Wei ◽  
Jie Hong ◽  
Gang Wei
Keyword(s):  
Principal Stress ◽  
Differential Settlement ◽  
Shield Tunnel ◽  
Tunnel Construction ◽  
Foundation Settlement ◽  
Ground Settlement ◽  
Shield Tunneling ◽  
Frame Building ◽  
Shield Machine ◽  
The Impact

Considering the interaction of building-soil-tunnel, the grillage beams foundation frame building vertical crossed by Double-O-Tube (DOT) shield tunnel was simulated by 3D MIDAS/ GTS software, and the impact of construction on the building was analyzed. The results show that: the ground settlement trough caused by DOT shield tunnel can be fitted by peck formula; during the passage of the shield tunneling through the building, the settlement of the building increased and settlement trough was wilder; the settlement was stable and had a little rebound when shield machine already passed the building; with the increase of driving distance, the first principal stress P1 increased and then was stable; with the increase of L, the shape of foundation settlement curve changed, and the maximum differential settlement between columns increased but was small.

Study on Thermal Cycling of Sn0.7Cu Solder

2013 ◽  
Vol 791-793 ◽  
pp. 362-365
Author(s):  
Li Yang ◽  
Ju Li Li ◽  
Jing Guo Ge ◽  
Meng Li ◽  
Nan Ji
Keyword(s):  
Shear Stress ◽  
Steady State ◽  
High Temperature ◽  
Thermal Cycling ◽  
Shear Strain ◽  
Maximum Shear Stress ◽  
Steady State Creep ◽  
Maximum Shear Strain ◽  
Cycle Number ◽  
State Cycle

Thermal cycling of a unit Sn0.7Cu solder was studied based on the steady-state creep constitutive equation and Matlab software. The results show that there is a steady-state cycle for the thermal cycling of unit Sn0.7Cu eutectic solder. In steady-state thermal cycling, the shear stress is increased with the increase of temperature. There is a stage of stress relaxation during high temperature. A liner relationship between maximum shear stress and maximum shear strain is observed during thermal cycling. The metastable cycle number is declined greatly with the increase of maximum shear strain.

scholarly journals Research on the Tunnel Excavated In Urumqi Glacier No. 1, Tianshan Glaciological Station, China

1987 ◽  
Vol 33 (113) ◽  
pp. 99-104 ◽  
Author(s):  
Huang Maohuan ◽  
Wang Zhongxiang
Keyword(s):  
Melting Point ◽  
Shear Strain ◽  
Maximum Shear Strain ◽  
Ice Surface ◽  
Basal Sliding ◽  
Glacier Ice ◽  
Glacier Motion

AbstractA tunnel was excavated in Urumqi Glacier No. 1, at the Tianshan Glaciological Station. Ice temperature, ice displacement, deformation, and basal sliding, etc. were observed at regular intervals. It is shown that the temperature near the glacier bed is close to the melting point and that the largest proportion of the overall glacier motion is within the lowermost ice layers. The glacier ice is in a state of compression. The maximum shear strain increases towards the entrance of the tunnel, corresponding to the change in slope of the ice surface, and also towards the bedrock.

Strengthening and Modernization of a Characteristic Masonry Building in Vienna, Austria

2020 ◽  
pp. 173-192
Author(s):  
Dimitrios Stefanoudakis ◽  
Eftychia Apostolidi
Keyword(s):  
Structural Analysis ◽  
Main Part ◽  
Analysis Data ◽  
Masonry Building ◽  
Historical Buildings ◽  
Building Stock ◽  
Before And After

Historical buildings from the period of Promoterism constructed between 1850 and 1910, called “Gründezeitgebäude,” represent a main part of the building stock in Vienna. A typical building from this period is presented, along with the pathology of such buildings. A step-by-step strengthening and modernization strategy is described, including structural analysis data and design of sections data before and after interventions, along with detailing according to the respective codes.

scholarly journals The theory of plane plastic strain for anisotropic metals

1949 ◽  
Vol 198 (1054) ◽  
pp. 428-437 ◽  
Keyword(s):  
Plastic Strain ◽  
Strain Rate ◽  
Shear Strain ◽  
Plane Strain ◽  
Yield Criterion ◽  
Elliptic Functions ◽  
Shear Strain Rate ◽  
Maximum Shear Strain ◽  
Geometrical Properties ◽  
Plane Plastic

A yield criterion and plastic stress-strain relations are formulated for anisotropic metals deformed under conditions of plane strain. The equations are shown to be hyperbolic, the characteristics coinciding with the directions of maximum shear strain-rate. When the anisotropy is uniformly distributed, the variation of the stresses along the characteristics is expressed in terms of elliptic functions, and geometrical properties of the field of characteristics are established. The theory is applied to the problem of indentation by a flat die.

Longitudinal movements and resulting shear strain of the arterial wall

2006 ◽  
Vol 291 (1) ◽  
pp. H394-H402 ◽  
Author(s):  
Magnus Cinthio ◽  
Åsa Rydén Ahlgren ◽  
Jonas Bergkvist ◽  
Tomas Jansson ◽  
Hans W. Persson ◽  
...  
Keyword(s):  
Blood Flow ◽  
Shear Strain ◽  
Arterial Wall ◽  
Ultrasonic Method ◽  
Vascular Diseases ◽  
Maximum Shear Strain ◽  
Healthy Humans ◽  
New Information ◽  
Early Systole ◽  
Diameter Change

There has been little interest in the longitudinal movement of the arterial wall. It has been assumed that this movement is negligible compared with the diameter change. Using a new high-resolution noninvasive ultrasonic method, we measured longitudinal movements and diameter change of the common carotid artery of 10 healthy humans. During the cardiac cycle, a distinct bidirectional longitudinal movement of the intima-media complex could be observed in all the subjects. An antegrade longitudinal movement, i.e., in the direction of blood flow, in early systole [0.39 mm (SD 0.26)] was followed by a retrograde longitudinal movement, i.e., in the direction opposite blood flow [−0.52 mm (SD 0.27)], later in systole and a second antegrade longitudinal movement [0.41 mm (SD 0.33)] in diastole. The corresponding diameter change was 0.65 mm (SD 0.19). The adventitial region showed the same basic pattern of longitudinal movement; however, the magnitude of the movements was smaller than that of the intima-media complex, thereby introducing shear strain and, thus, shear stress within the wall [maximum shear strain between the intima-media complex and the adventitial region was 0.36 rad (SD 0.26). These phenomena have not previously been described. Measurements were also performed on the abdominal aorta ( n = 3) and brachial ( n = 3) and popliteal ( n = 3) arteries. Our new information seems to be of fundamental importance for further study and evaluation of vascular biology and hemodynamics and, thus, for study of atherosclerosis and vascular diseases.

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