Safe and Rapid Construction Technology of Underground Large Section Chamber

2021 ◽  
Keyword(s):  
Construction Technology ◽  
Large Section ◽  
Rapid Construction

The Grouting Technology of Large-Section Highway Tunnel in Water-Rich Karst Formations

2013 ◽  
Vol 838-841 ◽  
pp. 1441-1446
Author(s):  
Chao Yue Zhou ◽  
Yong Fang ◽  
Ya Peng Fu ◽  
Ge Cui
Keyword(s):  
Cross Section ◽  
Field Tests ◽  
Operation Technique ◽  
Tunnel Construction ◽  
Construction Technology ◽  
Large Cross Section ◽  
Large Section ◽  
Highway Tunnel ◽  
Grouting Materials

It is a challenge to deal with karst in the construction of large cross-section tunnel. Under the background of Shuangbei Highway Tunnel, a new kind of grouting technology is introduced. According to hydrogeology, field tests are carried out to select grouting materials and proportion of mixture. Combined with the project practice, grouting construction technology is discussed such as grouting equipments, grouting parameters, operation technique, grouting ending standards. It has been proved that the technology is effective in tunnel construction.

scholarly journals Small Pilot Tunnel Advance and Step Reverse Expansion in Super-Large-Section Tunnel Excavation

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Bole Sun ◽  
Xiaorong Tang ◽  
Yongyi He ◽  
Mingnian Wang
Keyword(s):  
Production Efficiency ◽  
Expansion Method ◽  
Surrounding Rock ◽  
Construction Technology ◽  
Construction Time ◽  
Engineering Project ◽  
Large Section ◽  
Maximum Displacement ◽  
Tunnel Support ◽  
In Situ Conditions

Collapse of the vault and numerous other safety accidents often occur during the construction process of large-section tunnels. The utilization of a small pilot tunnel and a step reverse expansion construction methodology is proposed based on conventional construction methods to explore safe construction technology. First, a theoretical analysis combined with on-site monitoring parameters was conducted. It showed that the maximum displacement of the tunnel surrounding rock was 0.027 m during the elastic stage and increased to 0.031 m during the strength limit stage. The overall surrounding rock deformation does not have a noticeable impact on tunnel safety. A numerical simulation model of the small pilot tunnel advancement and step reverse expansion method was established. Simulation results showed that the first two excavation steps caused 89.6% of the total overlining strata subsidence, and the use of a small pilot tunnel advancement and step reverse expansion method can enhance the tunnel support. The tunnel surrounding rock was adequately stabilized after using this excavation method and provides the in-situ conditions for expanding the pilot tunnel to the large-section tunnel. The proposed method was adopted in an actual engineering project. It protected the subsequent construction of the main tunnel and decreased construction time, saving construction costs while ensuring safety, reducing construction risks, and improving production efficiency. This research can guide similar tunneling projects.

Research on Comprehensive Mechanized Efficient Construction Technology of Large Section Shaft in Hecaogou Mine

2013 ◽  
Vol 753-755 ◽  
pp. 853-856 ◽  
Author(s):  
Jie Kong ◽  
Qing Shu Liu ◽  
Yi Qi Zhu ◽  
Peng Chen ◽  
Hang An
Keyword(s):  
High Power ◽  
High Speed ◽  
Coal Mines ◽  
Drive Shaft ◽  
Scientific Management ◽  
Construction Technology ◽  
Large Section ◽  
Driving Speed ◽  
Efficient Construction ◽  
Management Method

With the mine shafts section and length increasing constantly, artificial shaft driving speed does not meet the need of modern large coal mines production and construction, using a set of comprehensive mechanized equipment to drive shaft is imperative. The length of bedrock section of auxiliary inclined shaft in Hecaogou mine is 1533.7m. The area of driving section is 21.6m2, belongs to large section super-long shaft. Hecaogou mine took the advantage of shafts comprehensive mechanized equipment, using high power EBZ318H fully-mechanized coal winning machine to drive, with scientific management method, realized safe and high-speed driving of inclined shaft, achieved good results that the highest speed was 227m per month, the effect was obviously. It has an actively practical meaning for other large section super-long shaft.

Rapid Construction Technology for Railroad Concrete Infrastructure: Microwave Heat Curing Technology

2015 ◽  
Author(s):  
Taehoon Koh ◽  
Seonkeun Hwang ◽  
Junghoon Yoo ◽  
Donggeun Lee
Keyword(s):  
Heating System ◽  
Curing Temperature ◽  
Cold Weather ◽  
Concrete Lining ◽  
Construction Technology ◽  
Construction Process ◽  
Construction Period ◽  
Heat Curing ◽  
Rapid Construction ◽  
Microwave Heat

The cast-in-place concrete lining construction process represents about 25% of the total railroad tunnel construction period. Moreover, the construction period for lining concrete depends on the speed of the curing process of the lining concrete. Therefore, in cold weather when the air temperature in mountain railroad tunnel is consistently 10 degrees or below, equipment for heat insulation of cast-in-place concrete lining, such as a portable fossil fuel heater, must also be prepared to maintain an appropriate curing temperature in the tunnel. It generally takes about 24 to 36 hours to reach the compressive strength (3 to 5MPa) required to remove the lining form. Recently, microwave heat curing technology has been developed as a way of substantially reducing the concrete curing time, to achieve a reduction in the total construction period. The microwave heating system developed in this technology is comprised of a microwave generator, cavity, insulator, and exothermic body (microwave irradiated pyrogen). In this system, microwaves generated from the magnetron are irregularly reflected inside the cavity, and rapidly heat up the exothermic body so that the heat is transferred to the lining form and the concrete in turn, resulting in the accelerated hydration of concrete. Based on the field test data from the construction of the railroad tunnel cast-in-place concrete lining, it is found that this technology is able in 6 to 12 hours to complete the curing of concrete lining sufficiently to remove the form. It is hoped that this approach will substantially reduce the construction period and cost of tunnel lining, even during cold-weather.

Study on Excavation Method of Tunnel with Super Cross-Section and Super Large Section Area Underpass Extra-High Building

2011 ◽  
Vol 250-253 ◽  
pp. 2057-2067
Author(s):  
Xue Fu Zhang ◽  
Jia Xiang Liu
Keyword(s):  
Cross Section ◽  
Surface Load ◽  
Construction Technology ◽  
Large Section ◽  
Main Building ◽  
Section Area ◽  
Single Side ◽  
Third Line ◽  
High Building ◽  
Excavation Methods

Because double side drift excavation method named eye excavation method has been a mature and reliable excavation method, it has normally been used in tunnels with super cross-section and super large section area. However, the construction speed using this method is very slow. One of reasons is that the construction technology of this method would be more and complex. The other is that all construction workers, materials, equipment would be extremely difficult for their up and down, and that the ballast rock would have to be moved by artificial when the upper step of the middle guide hole would be excavated. In this paper, to speed up the process of excavating tunnel with super cross-section and super large section area underpass extra-high building, the elastic-plastic numerical simulations for the tunnel named Industry and Trade Station of the third line in Chongqing Rail Transit were made in four excavation methods conditions. The four excavation methods is respectively the double side drift excavation method to the first excavation in main building side, the double side drift excavation method to the first excavation in podium side, the single side drift excavation method in the upper step to the first excavation in main building side and the single side drift excavation method in the upper step to the first excavation in podium side. The main building is named Industry and Trade building with 22 floors. The results showed that the single side drift excavation method in the upper step could Insure the building and tunnel when the support measures were reasonable, that the guide hole beside the little surface load should firstly be excavated by whether double side drift excavation method or single side drift excavation method, and that these would provide a reference for some similar engineering.

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