scholarly journals Quantitative Evaluation of Ground Movements Caused by Grouting during Shield Tunnelling in Clay

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.

2002 ◽  
Vol 39 (6) ◽  
pp. 1273-1287 ◽  
Author(s):  
Manuel Melis ◽  
Luis Medina ◽  
José M Rodríguez

The development of tunnelling projects under heavily populated cities has been rapidly increasing around the world during the last decades. Since tunnel construction can have disastrous effects on buildings, structures, and utilities near the excavation, construction methods have necessarily to provide maximum safety inside and outside the tunnel. To predict and correct dangerous ground movements due to the tunnelling works, the authors developed a numerical model to simulate the earth pressure balance (EPB) excavation procedure and injection to complement some deficiencies found in previous analytical or empirical subsidence estimating procedures. This model takes into account the full excavation sequence and has been validated by a large amount of monitoring data from the previous Madrid Metro extension. In the present paper, several predictive methods are used to predict the ground movements generated during a new Madrid Metro extension project consisting of 48 km of tunnel (1999–2003). At the end of the works the results will be compared with data from monitored sections placed in all five cities linked by the extension. Conclusions about the applicability and accuracy of the methods will be established with the aim of helping researchers and engineers in their future projects.Key words: ground movements, monitoring, numerical modelling and analysis, settlement, tunnels.


1974 ◽  
Vol 11 (3) ◽  
pp. 380-395 ◽  
Author(s):  
P. B. Attewell ◽  
I. W. Farmer

The paper describes the results of a field measurement program aimed at determining the ground movements created by the hand excavation of a 4.146 m diameter shield-driven tunnel at a depth of 29.3 m in stiff, fissured, heavily overconsolidated London clay. Approximately half of the recorded maximum surface settlement of 6.1 mm is both measured and calculated to have taken place during passage of the shield, the remainder being attributed to post-shield deformations. Calculations are based on a field and laboratory-determined average radial yield rate for the clay at the tunnel of 0.0055 mm/min. It is concluded that a normal probability surface settlement profile is developed over the shield and tail.Post-shield inward decompressions (K0 ≈ 1.65) and possible recompression as a clay–grout interaction effect could then be responsible for a slight reconsolidation of the clay at soffit and for distortion of the final settlement profile out of concordance with an error curve.


2011 ◽  
Vol 415-417 ◽  
pp. 1431-1434
Author(s):  
Wei Wei Yu ◽  
Xuan Guo

Characterization of geotechnical digging and control the dynamical settlement is very necessary to mitigate construction risk. The metro tunnels of being constructed access to each other or near to the ground is high risk and physically difficult and costly. The control method becomes imperative. Some cases of digging prediction of ground movements and assessment of risk of damage to above or adjacent constructions have become an important issue especially in urban projec. Ground adaptability characterization is the key of control the tunneling in complex geotechnical conditions both in rock and soft stratum. High and changed water-soil pressure also is risk factors to effect tunneling process. Beside discussion of risk mitigation associate to tunnel construction, the developing settlement control and simulations are given to describe the methods of control risk.


1999 ◽  
Vol 39 (3) ◽  
pp. 99-112 ◽  
Author(s):  
Tadashi Sugiyama ◽  
Toshiyuki Hagiwara ◽  
Toshi Nomoto ◽  
Masaaki Nomoto ◽  
Yutaka Ano ◽  
...  

2005 ◽  
Vol 42 (4) ◽  
pp. 1160-1172 ◽  
Author(s):  
Manuel Melis Maynar ◽  
Luis Medina Rodriguez

A detailed study on the available methods of predicting ground movements due to tunnelling works was carried out during the construction of the Madrid Metro extensions in 1995–1999 and 1999–2003. A total of 100 km were built and commissioned during this period. A numerical model was developed to simulate the earth pressure balance (EPB) excavation procedure and to complement some of the deficiencies found in previous analytical or empirical subsidence estimation procedures. Before the beginning of the works, a total of six different methods were used to estimate ground movements generated by the tunnelling works at some monitored sections placed in all five cities linked by the 1999–2003 extension, and the estimations were published in an earlier paper in this journal. Once all tunnelling works were finished and actual measurements carried out, a number of comparisons between predictions and measurements were made and are included in this paper. Conclusions about the applicability and accuracy of the methods are established with the aim of helping researchers and engineers in their future projects.Key words: ground movements, monitoring, numerical modelling and analysis, settlement, tunnels.


2018 ◽  
Vol 55 (6) ◽  
pp. 894-902 ◽  
Author(s):  
Dong-Jie Ren ◽  
Shui-Long Shen ◽  
Arul Arulrajah ◽  
Huai-Na Wu

This paper investigates the influence of moving trajectories on ground loss ratio (GRL) due to the double-O-tube (DOT) tunnelling method. DOT tunnelling has three moving trajectories: pitching, yawing, and rolling, which have different behaviours during tunnel construction compared with those from single circular shield tunnelling. These moving trajectories cause overexcavation during tunnelling. The calculation method of gap area between the DOT shield machine and linings is evaluated in this research. Based on the superposition concept, the modification equation of GLR is proposed, which takes both moving trajectory and grouting volume into consideration. A field DOT tunnelling case is analysed to determine the correlation between moving trajectories and ground settlement. The influence of tail grouting is discussed by adjusting the grouting volume in different periods. The finite element method is also employed by setting the modified ground loss ratio (GLR′) as the contraction increment of linings. Results from both the measured and simulated settlements verify the reasonability of the proposed equation and the effect of moving trajectories on ground loss.


Sign in / Sign up

Export Citation Format

Share Document