Zhou Shi

Bio: Zhou Shi is an academic researcher from Chang'an University. The author has contributed to research in topics: Rock mass classification & Deformation (meteorology). The author has an hindex of 6, co-authored 12 publications receiving 74 citations.

Deformation Behaviors and Mechanical Mechanisms of Double Primary Linings for Large-Span Tunnels in Squeezing Rock: A Case Study

Abstract: Large deformation has always been a focus and difficult issue in the construction of deep-buried tunnels in squeezing rock. Previous studies mainly focused on the large deformation of medium and small span railway/highway tunnels in soft ground. However, there are limited researches on the large deformation control methods for large-span (three-lane) highway tunnels constructed in unfavorable geological environment. Based on the Lianchengshan Tunnel of the Baoji-Hanzhong expressway in Shaanxi Province, China, this paper studied the deformation behaviors and mechanical mechanisms of a large-span tunnel excavated in chlorite schist formation with single primary lining method and double primary lining method by in-situ test and numerical simulation. The achieved results indicate that the double primary lining method is much more effective than that of the single primary lining method in restraining the deformation of surrounding rock, and the maximum vertical displacement and horizontal convergence are reduced by 67% and 66%, respectively. The support method of double HK200b-type steel sets combined with large-diameter foot reinforcement bolt (FRB) and deep invert could effectively control the large deformation of the case tunnel, which effectively avoided the supporting structure failure, repeated clearance invasion and multiple reshaping work caused by the single primary lining method and conformed to the energy-saving construction concept of “no clearance interfering, no support reshaping” of tunnels in squeezing ground. Simulation analysis of surrounding rock deformation, supporting structure stress and plastic zone distribution was performed to evaluate the support effect of the two deformation-controlled methods. Finally, the deformation and stress characteristic curves of rock-support of the two deformation-controlled methods were established, which revealed the supporting mechanism of double primary linings for large-span tunnels in chlorite schist. The research results can provide a theoretical basis and practical reference for the large-deformation control of similar large-span tunnels in squeezing rock.

Nonlinear deformation behaviors and a new approach for the classification and prediction of large deformation in tunnel construction stage: a case study

Abstract: Reasonable evaluation and prediction of squeezing condition to avoid large deformation disaster in tunnels have been an important research issue. In order to accurately and rapidly predict the larg...

Deformation Evolution and Failure Mechanism of Monoclinic and Soft-Hard Interbedded Strata: Study of Muzhailing Tunnel

Abstract: The large deformation issue in soft rock mass is a worldwide difficulty that has puzzled tunnel engineering for a century and a half. Previous studies have mainly focused on a large deforma...

Real-world automotive emissions: Summary of studies in the Fort McHenry and Tuscarora Mountain tunnels. Final report

Abstract: Motor vehicles are the main source of carbon monoxide (CO) Under multiple sponsorship, two major vehicle emissions studies were conducted: one in Fort McHenry tunnel (under the Baltimore Harbor) in June 1992 and the other in the Tuscarora Mountain tunnel in south-central Pennsylvania (Pennsylvania Turnpike) in September 1992 The cars at both sites tended to be newer than elsewhere (median age was < 4 years), and much better maintained as judged by low CO/CO2 ratios and other emissions characteristics Measured CO/CO2 ratios agreed with concurrent roadside infrared remote sensing measurements on light-duty vehicles Remote sensing measurements on heavy-duty diesels were obtained for the first time and were roughly in agreement with the regular (bag sampling) tunnel measurements in both CO/CO2 and HC/CO2 ratios

Deformation Behaviors and Mechanical Mechanisms of Double Primary Linings for Large-Span Tunnels in Squeezing Rock: A Case Study

Abstract: Large deformation has always been a focus and difficult issue in the construction of deep-buried tunnels in squeezing rock. Previous studies mainly focused on the large deformation of medium and small span railway/highway tunnels in soft ground. However, there are limited researches on the large deformation control methods for large-span (three-lane) highway tunnels constructed in unfavorable geological environment. Based on the Lianchengshan Tunnel of the Baoji-Hanzhong expressway in Shaanxi Province, China, this paper studied the deformation behaviors and mechanical mechanisms of a large-span tunnel excavated in chlorite schist formation with single primary lining method and double primary lining method by in-situ test and numerical simulation. The achieved results indicate that the double primary lining method is much more effective than that of the single primary lining method in restraining the deformation of surrounding rock, and the maximum vertical displacement and horizontal convergence are reduced by 67% and 66%, respectively. The support method of double HK200b-type steel sets combined with large-diameter foot reinforcement bolt (FRB) and deep invert could effectively control the large deformation of the case tunnel, which effectively avoided the supporting structure failure, repeated clearance invasion and multiple reshaping work caused by the single primary lining method and conformed to the energy-saving construction concept of “no clearance interfering, no support reshaping” of tunnels in squeezing ground. Simulation analysis of surrounding rock deformation, supporting structure stress and plastic zone distribution was performed to evaluate the support effect of the two deformation-controlled methods. Finally, the deformation and stress characteristic curves of rock-support of the two deformation-controlled methods were established, which revealed the supporting mechanism of double primary linings for large-span tunnels in chlorite schist. The research results can provide a theoretical basis and practical reference for the large-deformation control of similar large-span tunnels in squeezing rock.

Tunnelling-Induced Settlement and Treatment Techniques for a Loess Metro in Xi’an

Abstract: Techniques including pre-grouting, long pipe roof, and parameter optimization were employed to ensure the safety of loess metro tunnelling under an existing glass building. Their effects were proved through monitoring the settlement of building and surface during tunnelling. Besides, division of settlement monitoring according to processes, a new method, was conducted to control settlement in time. The highest surface settlement after construction was 16 mm only, meeting the requirement. The result indicates that it is practicable to control the tunnelling settlement strictly in extremely difficult geological areas. The settlement regularities were also studied through numerical simulation; their deformation is larger compared with in situ results while their change trends coincide during most processes. Soil excavations cause settlement primarily, accounting for more than 60%. It is suggested that dual slurry pre-grouting and process-based measurement should be employed before each excavation in water-rich loess areas.