Distribution Features of the Minimum Rock Cover Thickness of the Surrounding Rock Self‐Stability of the Metro Tunnel in the Soil‐Rock Dualistic Stratum

Zhang, Ziguang; Xu, Tao; Cao, Guizhou; Liu, Xiaofeng

doi:10.1155/2020/9120983

Cited by 3 publications

(2 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…e moderately weathered rock stratum and slightly (non)weathered rock stratum are collectively referred to as hard rock stratum. us, the binary strata of upper soil and lower rock are constructed [33]. A total of 17 geological exploration holes are arranged in the project site, including 6 control holes and 11 general holes.…”

Section: Typical Projectmentioning

confidence: 99%

Study on the Characteristics of Self‐Stabilizing Height Distribution for Deep Foundation Pit Vertical Sidewall in Binary Strata of Upper Soil and Lower Rock

Zhang

Zhang²,

et al. 2021

Advances in Civil Engineering

Self Cite

View full text Add to dashboard Cite

The self-stability height of the foundation pit sidewall is an important criterion for evaluating the safety degree and designing the supporting structure. The strength reduction elastic-plastic finite element numerical calculation method has been adopted in this paper. Based on comparative analysis of the stability characteristics for deep foundation pit in binary strata of upper soil and lower rock under multiple working conditions, the potential fracture surface of deep foundation pit and the evolution law of corresponding safety factor have been revealed under different Hs and H. A new idea that the vertical soil sidewall height (Hs) and the vertical rock sidewall height (Hr) are used as two independent evaluation indexes, respectively, for deep foundation pit stability in binary strata of upper soil and lower rock has been put forward. The distribution characteristics and variation law of Hs0 and Hr0 under different Hs and different H have been revealed, respectively. The spatial distribution map of the self-stabilizing height for deep foundation pit vertical sidewall in upper soil and lower rock binary stratum has been constructed, and the mathematical fitting equation between Hr0 and Hs has been obtained. Finally, combined with the implementation effect of the deep foundation pit project of Ningxia Road Station for Qingdao Metro Line 3, the rationality of the conclusions is verified. The research results provide theoretical basis for quickly determining the self-stability characteristics of foundation pit vertical sidewall.

show abstract

Section: Typical Projectmentioning

confidence: 99%

Study on the Characteristics of Self‐Stabilizing Height Distribution for Deep Foundation Pit Vertical Sidewall in Binary Strata of Upper Soil and Lower Rock

Zhang

Zhang²,

et al. 2021

Advances in Civil Engineering

Self Cite

View full text Add to dashboard Cite

show abstract

“…In practical engineering, stability analysis is usually evaluated from two aspects: the displacement of weak surrounding rock and the stress of supporting structure caused by tunnel construction. However, the existing research on supporting technology has mainly focused on the excavation of mine tunnels, especially tunnels under harsh geological conditions, such as extremely weak broken rock masses and soft soil [2][3][4], high tectonic stress, and other mine lanes [5][6][7][8]. The existing design methods of tunnel supporting structures mainly include the distributed ground pressure approach, subgrade reaction approach, and convergence-confinement method (CCM) [9].…”

Section: Introductionmentioning

confidence: 99%

Design of Tunnel Initial Support in Silty Clay Stratum Based on the Convergence-Confinement Method

Liu

Zhao

et al. 2023

Sustainability

View full text Add to dashboard Cite

The stress release ratio of the surrounding rock in tunnel excavation is one of the most important indicators that affect the stress distribution and displacement of the surrounding rock. To determine the variation law of the stress release ratio of the surrounding rock during excavation in silty clay stratum, the stress release law is determined based on the convergence–confinement method (CCM) and field test data. The stress release law of the surrounding rock under support is determined based on the displacement back analysis method. The permitted displacement safety factor of silty clay under different subgrade conditions and the optimal supporting time of the initial supporting structure are determined by comparing the stress release ratio with surrounding rock displacement. The results indicated that the stress release ratio of surrounding rock in the silty clay stratum is approximately 78–90% when the coordinate displacement of the supporting structure and surrounding rock is stable under the current excavation and support conditions. For the surrounding rock of subgrade V in the silty clay stratum, the safety factor of the permitted displacement in the tunnel vault is approximately 2.91, and the initial support should be carried out within 1 m behind the face advancing. For the surrounding rock of subgrade VI1, the safety factor of the permitted displacement is 1.40, and the initial support must be carried out 1 m ahead of the tunnel face. For the surrounding rock of grade VI2, the initial support must be carried out 4 m ahead of the tunnel face.

show abstract

Study on the Division of the Affected Zone under Construction Unloading and Its Construction Sequence of the Multiline Parallel River-Crossing Pipe Jacking

Ziguang,

Ruijin,

Jiesheng

et al. 2023

Advances in Civil Engineering

Self Cite

View full text Add to dashboard Cite

There are many advantages of reasonably determining the affected zone and its construction sequence for the multiline parallel pipe-jacking construction, such as convenient to reasonably arrange the pipeline section distribution mode, reducing the construction safety risk, and construction difficulty. Combined with the engineering construction practice of the multiline parallel pipe-jacking project for the north city drainage and flood control project through Chu River in Hefei, the strength reduction method has been utilized to study the surrounding stratum FOS for the pipe-jacking construction unloading under different overburden thickness Hs, different clear distance D, and different river water depth H w in this paper. The formula of the minimum critical overburden thickness Hsmin and the minimum critical clear distance Dmin of the surrounding stratum self-stability during pipe-jacking construction unloading have been derived. The division method of the affected zone for the multiline parallel river-crossing pipe-jacking construction which behaves as the mutual influence nonself-stability zone, the mutual influence self-stability zone, and the no mutual influence self-stability zone has been proposed. For further discussion, the construction sequence of the multiline parallel river-crossing pipe jacking has been studied.

show abstract

Distribution Features of the Minimum Rock Cover Thickness of the Surrounding Rock Self‐Stability of the Metro Tunnel in the Soil‐Rock Dualistic Stratum

Cited by 3 publications

References 28 publications

Study on the Characteristics of Self‐Stabilizing Height Distribution for Deep Foundation Pit Vertical Sidewall in Binary Strata of Upper Soil and Lower Rock

Study on the Characteristics of Self‐Stabilizing Height Distribution for Deep Foundation Pit Vertical Sidewall in Binary Strata of Upper Soil and Lower Rock

Design of Tunnel Initial Support in Silty Clay Stratum Based on the Convergence-Confinement Method

Study on the Division of the Affected Zone under Construction Unloading and Its Construction Sequence of the Multiline Parallel River-Crossing Pipe Jacking

Contact Info

Product

Resources

About