Research on Spacial Displacement Regulations in Soft Surrounding Rock Tunnel

2013 ◽  
Vol 690-693 ◽  
pp. 886-889
Author(s):  
Bao Long Lin
Keyword(s):  
High Speed ◽  
Surrounding Rock ◽  
Construction Process ◽  
High Speed Rail ◽  
Tunnel Stability ◽  
Construction Methods ◽  
Minimum Principal Stress ◽  
Initial Support ◽  
Rock Tunnel ◽  
Weak Surrounding Rock

Based on the engineering background of Dongkeling tunnel of Guizhou-Guangzhou high-speed rail, construction process in soft surrounding rock is simulated by using finite difference software——FLAC according to large-deformation characteristics in water-rich and weathering altered granite weak surrounding rock. Several aspects, such as vault settlement, invert uplift, clearance convergence, surface settlement, the maximum and minimum principal stress of the initial support and plastic zone of surrounding rock, are analyzed to determine the tunnel stability with different construction methods.

scholarly journals Study on the Treatment Timing of Large Deformation of the Tunnel in Swelling Rock

2018 ◽  
Vol 206 ◽  
pp. 01005
Author(s):  
Zhongmin Yang ◽  
Yongtao Gao ◽  
Ziqiao Cheng ◽  
Zijie Cong
Keyword(s):  
Large Deformation ◽  
Surrounding Rock ◽  
Stress Release ◽  
Construction Time ◽  
Treatment Timing ◽  
Final Stress ◽  
Initial Support ◽  
Swelling Rock ◽  
Rock Tunnel ◽  
Deformation Treatment

When large deformation of the tunnel occurred in the swelling rock, the large deformation treatment will not only greatly delay the construction time, but also lead to instability or even collapse of the tunnel. Selecting the reasonable timing for large deformation initial support replacement can solve this problem effectively. Based on the LiRang tunnel, the deformation and stress of the tunnel in anhydrite were analysed by FLAC software after excavation. Then replace the deformed first liner at different vault settlement value. The displacement and stress of surrounding rock were analysed when the model reaches equilibrium state again. The results showed that stress concentration at the arch wall and arch foot of the tunnel, and the stress release at the vault and invert is very large after excavation. If the large deformation was treatment when the crown settlement of the tunnel reaches 90% ~95% of the final predicted settlement value, the tunnel deformation and the final stress state could be in a small value. This study can provide a reference for the treatment of large deformation in the swelling rock tunnel.

scholarly journals Fine Exploration and Control of Subway Crossing Karst Area

2019 ◽  
Vol 9 (13) ◽  
pp. 2588 ◽  
Author(s):  
Jing Wang ◽  
Liping Li ◽  
Shaoshuai Shi ◽  
Shangqu Sun ◽  
Xingzhi Ba ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Treatment Method ◽  
Surrounding Rock ◽  
Karst Area ◽  
Actual Situation ◽  
Construction Process ◽  
Tunnel Stability ◽  
Field Displacement ◽  
The Stability ◽  
And Control

A large number of subway projects need to cross all kinds of disaster sources during the construction process. When a disaster source is unknown and uncertain, it is difficult for tunnel stability analysis to conform to the actual situation, which is likely to cause serious geological disasters. Firstly, the accurate location of the source of the disaster is realized via the geophysical method, and the orientation of the target is determined. Secondly, real imaging of the geological disaster source is realized using fine three-dimensional scanning equipment. Finally, the coupling law of the seepage field, displacement field, and stress field of the tunnel surrounding rock are analyzed. The stability of the tunnel is analyzed, and the reasonable karst treatment method is put forward.

High Speed Rail: Track Construction Considerations

2011 ◽  
Author(s):  
Blaine O. Peterson
Keyword(s):  
High Speed ◽  
Optimal Solution ◽  
Rolling Stock ◽  
High Speed Rail ◽  
Track Geometry ◽  
Slab Track ◽  
Passenger Rail ◽  
Construction Methods ◽  
Track System ◽  
Ballasted Track

This paper discusses general High Speed Rail (HSR) track geometry, construction and maintenance practices and tolerances. The discussion will reference several key international projects and highlight different construction methods and the track geometry assessments used to establish and ensure serviceability of a typical HSR system. Historically, established tighter tolerances of “Express” HSR (i.e. operating speeds greater than 240 km/h or 150 mph) systems have favored the use of slab track systems over ballasted track systems. Slab track systems offer greater inherent stability while ballasted track systems generally require more frequent track geometry assessments and anomaly-correcting surfacing operations. The decisions related to which system to use for a given application involve numerous considerations discussed only briefly in this paper. In many cases, the optimal solution may include both track forms. Rolling stock considerations and their influence on track infrastructure design are considered beyond the scope of this paper. This paper will focus predominantly on two slab track systems widely used in international HSR projects: the Japanese J-slab track system; and the German Rheda slab track system. The French track system will be referenced as the typical ballasted track HSR design. The practices discussed in this paper generally apply to systems which are either primarily or exclusively passenger rail systems. In the U.S., these types of systems will necessarily exclude the systems the Federal Railway Administration (FRA) refers to as “Emerging” or “Regional” HSR systems which include passenger train traffic to share trackage on, what are otherwise considered, primarily freight lines.

scholarly journals Design and construction of simple beam bridges for high-speed rails in China: standardization and industrialization

2016 ◽  
Vol 11 (4) ◽  
pp. 274-282 ◽  
Author(s):  
Gonglian Dai ◽  
Miao Su ◽  
Y. Frank Chen
Keyword(s):  
High Speed ◽  
Rapid Development ◽  
Eastern China ◽  
Experimental Tests ◽  
High Speed Rail ◽  
Load Models ◽  
Construction Methods ◽  
Construction Experience ◽  
Dynamic Performances ◽  
Design And Construction

High-speed rail provides a safe, efficient, and economic transportation system for regions with high population density such as eastern China. To accommodate the rapid development of high-speed rails in China, the bridges with standard spans have been identified as the main infrastructure type. This article provides a state-of-the-art review on the design and construction of the standard simply-supported beam (simple beam) bridges for high-speed rails in China. The structural components discussed include the main girder, deck, and substructure. The live load models, deformation limiting values, and construction methods for the bridges are also discussed. Additionally, the experimental tests were conducted to verify the static and dynamic performances of the structure. The main objective of this paper is to provide the latest design and construction experience of Chinese standard simple beam bridges in high-speed rail and show how a quick and quality engineering has been achieved by utilizing these standardized bridges.

Study on Construction Method of Double-Track Tunnel on Passenger Dedicated Line by Numerical Simulation

2012 ◽  
Vol 204-208 ◽  
pp. 1527-1531
Author(s):  
Jian Guo Zhang
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Construction Method ◽  
Surrounding Rock ◽  
Construction Process ◽  
Construction Methods ◽  
Operation Conditions ◽  
Stability Of Surrounding Rock ◽  
Double Track ◽  
Passenger Dedicated Line

In view of the double-track tunnel on passenger dedicated line with speed 250km/h, finite element programming has been employed to simulate dynamic construction process under shallow-buried and bias conditions with grade IV, including stony and soil, and grade V surrounding rock. Different construction methods under various operation conditions have been compared. Based on stability of surrounding rock and safety of primary and temporary lining, proper construction method under various operation conditions has been presented.

scholarly journals Tunneling and other engineering works in volcanic environments: Sousaki and Thessaly

2007 ◽  
Vol 40 (4) ◽  
pp. 1733 ◽  
Author(s):  
C. Tsatsanifos ◽  
V. Kontogianni ◽  
S. Stiros
Keyword(s):  
High Speed ◽  
High Speed Rail ◽  
Safety Measures ◽  
Quaternary Volcanism ◽  
Volcanic Arc ◽  
Underground Opening ◽  
Tunnel Stability ◽  
The Past ◽  
Construction Techniques ◽  
Of Greece

This study is inspired by the impacts on a tunnel of the Sousaki volcano, in the vicinity of Corinth and examines possible impacts of the Quaternary volcanism on major engineering works in Thessaly. The Sousaki volcano, at the NW edge of the Aegean Volcanic Arc has been associated with important volcanic activity in the past, but its current activity is confined to géothermie phenomena. A tunnel for the new Athens-Corinth High Speed Rail was excavated through the solfatara of the volcano, an area characterized by numerous faults and physical cavities. High temperatures and geothermal gases released in the underground opening through the faults caused disturbance to the tunnel construction, need for supplementary investigations and adoption of special measures to maintain tunnel stability. Experience from the tunnel at Sousaki indicates that similar risks may be faced in future major engineering works in other regions of Greece. Such an example is the area of Microthives and Achillio, Magnesia, Thessaly. Tunnels for the new highway and railway networks constructed or planned through at least two volcanic domes and other main engineering works may also face volcano-associated effects. Optimization of the network routes in combination with special construction techniques and safety measures need to be followed for minimization of such volcanic risks.

scholarly journals Study on Key Steps of Three-lane Weak Surrounding Rock Tunnel Construction

2019 ◽  
Vol 304 ◽  
pp. 032010
Author(s):  
Chao Wang ◽  
Hongyan Guo ◽  
Xiangyang Cui ◽  
Ke Li ◽  
Hao Ding
Keyword(s):  
Surrounding Rock ◽  
Tunnel Construction ◽  
Rock Tunnel ◽  
Key Steps ◽  
Weak Surrounding Rock

Studies on Influence of Tunnel Surrounding Rock Stability Analysis Based on Material Yield Criterions

2011 ◽  
Vol 90-93 ◽  
pp. 501-507
Author(s):  
Mu Kun Huang ◽  
Xiao Guang Jin ◽  
Yan Wang ◽  
Ling Zhu
Keyword(s):  
Stability Analysis ◽  
Yield Criterion ◽  
Surrounding Rock ◽  
Tunnel Construction ◽  
Rock Stability ◽  
Element Simulation ◽  
Angle Point ◽  
Rock Tunnel ◽  
Weak Surrounding Rock ◽  
The Impact

Numerical simulation is one of main methods for tunnel surrounding rock stability analysis. By now, there hasn’t be unanimous view on that what kind of yield criterion is adopted for different surrounding rock class and different buried depth. Mohr-Coulomb yield criterion is always adopted abroad, Drucker-Prager yield criterion is always adopted in China, moreover, the principles are different when adopting D-P yield criterion at home and abroad. Based on introducing the Mohr-Coulomb yield criterion and D-P yield criterions, this paper uses the M-C exterior angle point of circle criteria, which is popular in the international arena for the D-P yield criterion, and finds parameters of geotechnical material for D-P yield criterions through the parameter transformation. Combining with 3D elastic-plastic finite element simulation of the tunnel construction process, with the tunnel buried by soft and weak surrounding rock (V class) at shallow (15m) and deep (550m), this paper analyzes the impact of the M-C and D-P yield criterions on surrounding rock’s displacement, stress, strain effects, and proposes the appropriate yield criterion for the simulation of shallow and deep soft and weak rock tunnel construction and for tunnel surrounding rock stability analysis.

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