Construction efficiency of shield tunnelling through soft deposit in Tianjin, China

2021 ◽  
Vol 112 ◽  
pp. 103917
Author(s):  
Tao Yan ◽  
Shui-Long Shen ◽  
Annan Zhou ◽  
Hai-Min Lyu
2011 ◽  
Vol 368-373 ◽  
pp. 2526-2532
Author(s):  
Yu Jia ◽  
Long Cai Yang ◽  
Jian Guo Liu

Aiming at medium distance transportation of excavated spoil and constructional components in the tunnelling process, this paper combines with a water-conveyance tunnel engineering and analyzes the influence factors that affect the construction efficiency of earth pressure balance shield(EPB shield), and then works out an available scheme based on that the transport link should well match with shield tunnelling. The field condition indicates that the equipment lectotype, marshaling and transport organization in this scheme guarantee the transport capacity and continuity for tunnelling, which ensures construction progress. The idea in this design can provide similar engineering with reference.


Data in Brief ◽  
2021 ◽  
pp. 107103
Author(s):  
Tao Yan ◽  
Shui-Long Shen ◽  
Annan Zhou ◽  
Hai-Min Lyu

2021 ◽  
Vol 13 (6) ◽  
pp. 3535
Author(s):  
Byung-Ju Jeon ◽  
Byung-Soo Kim

The Korean government proposed a goal to reduce its greenhouse gas emissions by 37% compared to business-as-usual levels by 2030 and launched the Green Standard for Energy and Environmental Design (G-SEED) certification system. The certification requires meeting the required score and material selection with a secured economy and construction efficiency. However, most buildings only focus on obtaining the certification scores instead of choosing economical materials with high construction efficiency. This research focused on developing a material selection model that considers both the construction efficiency and economy of the materials and the acquisition of material and resource evaluation scores from the G-SEED certification. This research, therefore, analyzed actual data to automate the material selection and compare alternatives to using a genetic algorithm to obtain optimized alternatives. This model proposes an alternative to constructability and economy when the required score and material information is entered. When the model was applied to actual cases, the result revealed a reduction in construction costs of about 37% compared to the cost with the traditional methods. The material selection model from this research can benefit construction project owners in terms of cost reduction, designers in terms of structural design time, and constructors in terms of construction efficiency


2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Zhi-Feng Wang ◽  
Wen-Chieh Cheng ◽  
Ya-Qiong Wang

Grouting has been deemed as one of the most effective measures for mitigation of ground movements during tunnel construction in soft soil. Notwithstanding that, a reliable measure to quantitatively evaluate the grouting-induced ground movements during shield tunnelling in soft soil has not yet been developed. This paper presents a simple method capable of quantitatively estimating the ground movements associated with grouting for tunnel-boring operations where the grouting parameters and soil properties are taken into consideration. The grouting process is simplified as the expansion of a cylindrical cavity with a uniform radial stress applied at soil-grout interface in a half plane, and the analytical solution proposed by Verruijt is introduced for determining the ground movements by the expansion of the cylindrical cavity. The proposed method is verified with a case history undertaken in London Clay. The results obtained suggest that this procedure would be helpful in managing the grouting parameters adopted in upcoming soft ground tunnelling project and mitigating the environmental impacts on nearby properties.


2021 ◽  
Vol 11 (6) ◽  
pp. 2551
Author(s):  
Hyobum Lee ◽  
Hangseok Choi ◽  
Soon-Wook Choi ◽  
Soo-Ho Chang ◽  
Tae-Ho Kang ◽  
...  

This study demonstrates a three-dimensional numerical simulation of earth pressure balance (EPB) shield tunnelling using a coupled discrete element method (DEM) and a finite difference method (FDM). The analysis adopted the actual size of a spoke-type EPB shield tunnel boring machine (TBM) consisting of a cutter head with cutting tools, working chamber, screw conveyor, and shield. For the coupled model to reproduce the in situ ground condition, the ground formation was generated partially using the DEM (for the limited domain influenced by excavation), with the rest of the domain being composed of FDM grids. In the DEM domain, contact parameters of particles were calibrated via a series of large-scale triaxial test analyses. The model simulated tunnelling as the TBM operational conditions were controlled. The penetration rate and the rotational speed of the screw conveyor were automatically adjusted as the TBM advanced to prevent the generation of excessive or insufficient torque, thrust force, or chamber pressure. Accordingly, these parameters were maintained consistently around their set operational ranges during excavation. The simulation results show that the proposed numerical model based on DEM–FDM coupling could reasonably simulate EPB driving while considering the TBM operational conditions.


Symmetry ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 746
Author(s):  
Xinquan Wang ◽  
Cong Zhu ◽  
Hongguo Diao ◽  
Yingjie Ning

The retaining wall is a common slope protection structure. To tackle the current lack of sustainable and highly prefabricated retaining walls, an environmentally friendly prefabricated ecological grid retaining wall with high construction efficiency has been developed. Due to the asymmetrical condition of the project considered in this paper, the designed prefabricated ecological grid retaining wall was divided into the excavation section and the filling section. By utilizing the ABAQUS finite element software, the stress and deformation characteristics of the retaining wall columns, soil, anchor rods, and inclined shelves in an excavation section, and the force and deformation relationships of the columns, rivets, and inclined shelves in three working conditions in a filling section were studied. The study results imply that the anchor rods may affect the columns in the excavation section and the stress at the column back changes in an M-shape with height. Moreover, the peak appears at the contact point between the column and the anchor rod. The displacement of the column increases slowly along with the height, and the column rotates at its bottom. In the excavation section, the stress of the anchor rod undergoes a change at the junction of the structure. The inclined shelf is an open structure and is very different from the retaining plate structure of traditional pile-slab retaining walls. Its stress distribution follows a repeated U-shaped curve, which is inconsistent with the trend of the traditional soil arching effect between piles, which increases first and then decreases. For the retaining wall structure in the filling section, the numerical simulated vehicle load gives essentially consistent results with the effects of the equivalent filling on the concrete column.


PAMM ◽  
2009 ◽  
Vol 9 (1) ◽  
pp. 215-216 ◽  
Author(s):  
Felix Nagel ◽  
Janosch Stascheit ◽  
Günther Meschke

Sign in / Sign up

Export Citation Format

Share Document