scholarly journals Research on Ground Settlement Regularity of Soft Rock Tunnel under Ultrasmall Distance

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Chunwu Zhang ◽  
Wei Hou ◽  
Zongjun Sun ◽  
Li Gu
Keyword(s):  
Soft Rock ◽  
Road Construction ◽  
Surface Settlement ◽  
Tunnel Construction ◽  
Ground Settlement ◽  
The Road ◽  
Total Settlement ◽  
Rock Tunnel ◽  
Reinforcement Measures ◽  
Tunnel Depth

During the tunnel construction under the road, the shallower the tunnel depth, the greater the effect of the surface settlement. Thus, to analyze the ground settlement caused by tunnel construction under ultrasmall distance, the research is based on a tunnel in Ningqiang County and uses numerical simulation and measurement to analyze the ground settlement and the effect of reinforcement measures. The research draws the following conclusions. For the ultrasmall distance tunnel under road construction, the combination of pipe shed and advanced small pipe grouting reinforcement measures inhibits the surface settlement. After the advanced small pipe is reinforced, the surface settlement value is reduced by about 25%, and the reinforcement effect is more obvious after the increase of the large pipe shed. The surface settlement value is reduced by about 60%. The surface settlement caused by the excavation of the circular soil accounts for about 50%–60% of the total settlement value, which is for the whole construction. The key processes, which involve the combination of reinforcement measures, focused on the suppression of surface settlement caused by the excavation of the circular soil. After the reinforcement measures, the variation of the settlement groove width was not obvious but the curvature and peak value of the settlement groove is reduced significantly.

Prediction of Shield Tunnelling-Induced Ground Settlement Considering Soil-Water Coupled and around Soil Disturbance Damage

2010 ◽  
Vol 168-170 ◽  
pp. 357-364
Author(s):  
Ji Feng Liu ◽  
Bo Liu ◽  
Hui Zhi Zhang
Keyword(s):  
Numerical Simulation ◽  
Soil Water ◽  
Ground Surface ◽  
Soil Disturbance ◽  
Surface Settlement ◽  
Shield Tunnel ◽  
Tunnel Construction ◽  
Ground Settlement ◽  
Ground Surface Settlement ◽  
Shield Tunnelling

to evaluate the influence of soil-water coupled and shield tunnel construction induced around soil disturbance damage on ground surface settlement, the process of shield tunnel construction induced around soil disturbance is analyzed, the FLAC3D numerical simulation are carried out, and a newly-modified tunnelling-induced ground settlement calculation method based on disturbance degree of around soil and soil-water coupled is presented, and these methods are applied in case of Beijing Metro 10thLine. It is indicated that considering the influence of the shield tunnelling-induced around soil disturbance damage, and soil-water coupled induced soil properties weakening and the excess pore water pressure dissipating induced soil consolidation to the ground surface settlement are necessary, the calculating result of the newly-modified surface settlement prediction method, and the result FLAC3D numerical simulation all agree well with in-site observed data of Beijing Metro 10th Line.

scholarly journals Ground Surface Settlement Evaluation by Proportional Hazards Model in Tunneling Projects

2021 ◽  
Author(s):  
Ali Kazempour Osalou ◽  
sayfoddin moosazadeh ◽  
Ali Nouri Qarahasanlou
Keyword(s):  
Risk Factors ◽  
Ground Surface ◽  
Injection Pressure ◽  
Surface Settlement ◽  
Proportional Hazard ◽  
Ground Settlement ◽  
Cohesion Strength ◽  
Proportional Hazard Model ◽  
Ground Surface Settlement ◽  
Tunnel Depth

Abstract Nowadays, tunnel excavation plays a major role in development of countries. Due to the complex and challenging ground conditions, a comprehensive study and analysis must be done before, during and also after the excavation of tunnels. Hence, the importance of study and evaluation of ground settlement are dramatically increased, since many tunnel projects are performed in the urban areas where there are plenty of constructions, buildings and facilities. For this reason, the control and prediction of ground settlement is one of the complicated topic in the fields of risk engineering. Therefore, in this paper, proportional hazard model (PHM) is used to analyze and study the ground settlement induced by Tabriz Metro Line 2 (TML2) tunneling. The PHM method is a semi-parametric regression method that can enter environmental conditions or factors affecting settlement probability. These influential factors are used as risk factors in the analysis. After establishing a database for a case study and using proportional hazard model for surface settlement analysis, and then, by evaluating the effect of environmental conditions on the ground surface settlement, it has been found that the risk factors of grouting pressure behind the segment, the ratio of tunnel depth to groundwater level, and drained cohesion strength at a significant level of 5% have a direct effect on the probability of settlement. The results also showed that the effect of grout injection pressure on ground subsidence is more than other parameters, and with increasing injection pressure, the probability of exceeding safe subsidence values decreases. In addition, it has been found that increasing the risk factor for the ratio of tunnel depth to groundwater level reduces the probability of exceeding the safe ground settlement. Finally, increasing the number of risk factors for drained cohesion strength increases the probability of exceeding safe settlement.

Control Standard of Ground Surface Settlement Induced by Running Tunnel Construction in Beijing Subway

2011 ◽  
Vol 117-119 ◽  
pp. 721-725 ◽  
Author(s):  
Cheng Ping Zhang ◽  
Li Min Li ◽  
He Li ◽  
Jian Chen Wang
Keyword(s):  
Numerical Simulation ◽  
Ground Surface ◽  
Control Valve ◽  
Surface Settlement ◽  
Tunnel Construction ◽  
Ground Settlement ◽  
Simulation Based ◽  
Ground Surface Settlement ◽  
Subway Construction ◽  
Beijing Subway

Ground settlement, especially the ground surface settlement induced by subway tunneling is an important issue. However, there is no an agreed standard for controlling ground surface settlement during the subway construction at present. The control standard of ground surface settlement was studied using the methods of statistical analysis and numerical simulation based on the running tunnel in Beijing subway. According to the research results, a conclusion could be obtained that the ground surface settlement can be controlled within 40 mm using the general construction measures in Beijing subway running tunnel construction, and furthermore, the settlement of 40mm will not damage the existing nearby structures and utilities including neighboring buildings, bridges and pipelines, etc. So the control valve of 40 mm is rational, which can be adopted as the control standard of ground surface settlement induced by running tunnel construction in Beijing subway.

scholarly journals Investigation of surface settlement of ground caused by cut-and-cover tunneling in Urmia Interchange

2020 ◽  
Author(s):  
Chiya Gharakhan
Keyword(s):  
Numerical Modelling ◽  
Ground Level ◽  
Surface Settlement ◽  
Soil Parameters ◽  
Tunnel Construction ◽  
Ground Settlement ◽  
Local Data ◽  
Maximum Settlement ◽  
Laboratory Parameters ◽  
Plaxis 3D

Earth's surface settlement is one of the most important tunnel drilling circumstances that has been studied by many international investigations to control its effects. This paper investigates the effect of cut-and-cover tunnel construction at the ground level adjacent to the non-surface interchange of the Urmia city, Iran. At the beginning of this research, the measurement of the Earth's ground settlement at some section of the non-surface interchange that is obtained from local surveys is provided. At the next step, it is compared with the analytical results of PLAXIS 3D and local data and soil parameters. The exact surface, obtained from the regional organization, was used to measure the Earth's ground settlement. According to the results obtained from the measurements, the maximum settlement is 9.95 mm. The calculated subsidence value of numerical modelling is lower than the results of local surveys, which may be due to the accuracy of soil laboratory parameters. At the end of the research, the actual soil parameters were obtained using recursive analysis. The measured session values are within the range of the results of other researchers.

scholarly journals Analytical Method for Evaluating the Ground Surface Settlement Caused by Tail Void Grouting Pressure in Shield Tunnel Construction

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Changsheng Wu ◽  
Zhiduo Zhu
Keyword(s):  
Elastic Modulus ◽  
Ground Surface ◽  
Surface Settlement ◽  
Shield Tunnel ◽  
Tunnel Construction ◽  
Grouting Pressure ◽  
Ground Surface Settlement ◽  
Tunnel Depth ◽  
Surface Heave ◽  
Surrounding Soil

The tail void grouting is a key step in shield tunnel construction and has an important influence on the loading on the surrounding soil and on the resulting settlement. In order to estimate the ground surface settlement caused by tail void grouting pressure in tunnel construction, the loading on the surrounding soil is simplified as an expansion problem of the cylindrical cavity in semi-infinite elastic space. A simple analytical formula is deduced by using the virtual image technique and Fourier transform solutions. The effectiveness of the proposed method is verified by case studies. The effects of elastic modulus, tail void grouting pressure, tunnel radius, and tunnel depth on the ground surface heave are conducted. The results indicate that the computed results are in accordance with Ye’s solution and it is more rational to consider the ground surface heave induced by tail void grouting pressure in the prediction of ground settlement due to shield excavation. Moreover, the ground surface heave owing to tail void grouting pressure resembled a Gaussian distributed curve. Thus, no matter the ground surface subsidence or ground surface heave can be predicted by means of adding the presented empirical formula to the Peck formula which cannot predict the ground surface heave. The ground surface heave decreases with an increase in elastic modulus. On the contrary, as the tail void grouting pressure and tunnel radius increase, the ground surface heave increases, respectively. The ground surface heave first steadily increases and then declines gradually with the tunnel depth increase.

scholarly journals Construction Technology of Large-deformation High Geostress Soft Rock Tunnel

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Xuguang Zheng ◽  
Heng Zhang ◽  
Xuesong Su
Keyword(s):  
Large Deformation ◽  
Soft Rock ◽  
Tunnel Construction ◽  
Construction Technology ◽  
Continuous Growth ◽  
Geological Disasters ◽  
High Geostress ◽  
Rock Tunnel ◽  
To Receive

In the process of tunnel construction, if large-deformation occurs in high geostress soft rock, it will likely cause geological disasters. This situation will not only seriously affect the smooth progress of tunnel construction, but also cause serious safety threat to the construction personnel. Therefore, with the continuous growth in the number and scale of tunnel construction in recent years, the construction technology for high geostress soft rock with large-deformation has begun to receive more and more attention from the society. Based on this, this paper takes an actual project as an example to analyze the specific application of the technology in order to improve the construction effect and avoid the damage caused by the large-deformation of the high geostress soft rock.

Analysis of Temporal-Spatial Effect for Tunnel Construction in the Fault-Rupture Zone

2011 ◽  
Vol 90-93 ◽  
pp. 1981-1986 ◽  
Author(s):  
Da Li ◽  
Xiao Xu Li ◽  
Yong Sheng Li ◽  
Zhan Fu Luo
Keyword(s):  
Soft Rock ◽  
Spatial Effect ◽  
Rupture Zone ◽  
Tunnel Construction ◽  
Fault Rupture ◽  
Optimum Time ◽  
Tunnel Excavation ◽  
Research Results ◽  
Secondary Lining ◽  
Rock Tunnel

Based on the existing research results, this paper proposes a temporal-spatial relational expression of displacements of tunnel perimeter during tunnel excavation. Taking Guanjiao tunnel as example, using the expression, temporal-spatial effect for Guanjiao tunnel in the fault-rupture zone are analyzed and studied. Comparison of theoretical solutions with measurements has proved that temporal-spatial effect for soft rock tunnel can be reflected by the expression and these results provide reasonable proposal for the optimum time to construct the secondary lining.( the constructing time of secondary lining) and reserved deformation.

Rheology-Based Stability Analysis of Soft Rock Tunnel in Construction Suspension

2014 ◽  
Vol 934 ◽  
pp. 129-135
Author(s):  
Su Min Zhang ◽  
Yong Quan Zhu
Keyword(s):  
Stability Analysis ◽  
Cross Section ◽  
Back Analysis ◽  
Soft Rock ◽  
Calculation Model ◽  
Surrounding Rock ◽  
Tunnel Construction ◽  
Rock Tunnel ◽  
Primary Support ◽  
Water Contents

Suspension in tunnel construction usually cause tunnel callapse in weak ground if the suspension time is long. Dongkeling tunnel on Guizhou-Guangxi line being as the engineering background, the indoor rheological experiment and back analysis were performed to obtain the rheological model and parameters of the surrounding rock, and the 3D viscoelasto-plastic calculation model was established to find the evolving rules of deformation at critical locations under two different water contents. It was found that the primary support has little effect on rheology of tunnel work face but on the cross section, and decreasing the water content of the surrounding rock to medium or low saturation level favors the tunnel stabillity greatly for water abundent tunnels.

scholarly journals Influence of Subway Shield Tunnel Construction on Ground Settlement

2021 ◽  
Vol 276 ◽  
pp. 02003
Author(s):  
Yilei Zhang ◽  
Jianxun Ma ◽  
Dan Cheng ◽  
Wenxiao Li
Keyword(s):  
Surface Settlement ◽  
Shield Tunnel ◽  
Tunnel Construction ◽  
Ground Settlement ◽  
Factors Affecting ◽  
Driving Speed ◽  
Consolidation Settlement ◽  
The Common

Shield construction has the advantages of stable driving speed, saving manpower, and being able to carry out construction in complex strata, which has been more and more widely used. In the process of shield construction, there is a gap between shield body and segment, which is easy to cause ground settlement when the grouting speed cannot keep up. This paper summarizes the common methods to predict the surface settlement, analyzes the causes of the settlement, and lists an engineering case to illustrate the factors affecting the surface settlement. Finally, it comes to the conclusion that the main causes of the surface settlement caused by shield tunnel construction are formation loss and consolidation settlement, and the use of small cutterhead and composite cutterhead can reduce the surface settlement, It provides a reference for the development of shield construction.

The Political Economy of Power: Approaches to the Analysis of Relationships between the State and Business in Russia

2011 ◽  
pp. 19-33
Author(s):  
A. Oleinik
Keyword(s):  
Oil And Gas ◽  
Road Construction ◽  
Oil And Gas Industry ◽  
Retail Trade ◽  
Business Community ◽  
The Political ◽  
Economic Power ◽  
Gas Industry ◽  
The Road ◽  
Ruling Elites

The article deals with the issues of political and economic power as well as their constellation on the market. The theory of public choice and the theory of public contract are confronted with an approach centered on the power triad. If structured in the power triad, interactions among states representatives, businesses with structural advantages and businesses without structural advantages allow capturing administrative rents. The political power of the ruling elites coexists with economic power of certain members of the business community. The situation in the oil and gas industry, the retail trade and the road construction and operation industry in Russia illustrates key moments in the proposed analysis.

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