Tunnel Prospecting Based on Integrated Interpretation of Geophysical Data: Xiangyun Tunnel, Yunnan Province, China

2019 ◽  
Vol 24 (1) ◽  
pp. 63-75
Author(s):  
Lei Chen ◽  
Fengkai Zhang ◽  
Yuxiao Ren ◽  
Xinji Xu ◽  
Zhichao Yang ◽  
...  
Keyword(s):  
Yunnan Province ◽  
Geological Mapping ◽  
Tunnel Construction ◽  
Tunnel Excavation ◽  
Horizontal Drilling ◽  
Adverse Conditions ◽  
Transient Electromagnetic ◽  
Geological Conditions ◽  
Electromagnetic Soundings ◽  
Integrated Interpretation

With China's expanding economy, many tunnels are being designed and constructed. However, tunneling in hazardous geologic terrain, with faults, fractures, water-bearing openings, and other adverse geological conditions, construction safety is seriously endangered. To ensure the safety of tunnel construction, a tunnel geological prospecting method was proposed and applied at the Xiangyun Tunnel in Yunnan Province, China. In the investigation stage, the engineering geological and hydrogeological conditions were analyzed to recognize high-risk sections. In the construction stage, the “tunnel ahead” prospecting scheme was optimized based on the macroscopic geological conditions. Geological mapping of the tunnel, seismic ahead prospecting and transient electromagnetic soundings were employed as well as resistivity models to image potential adverse conditions. Horizontal drilling and tunnel excavation records verified the geophysical predictions and interpretations.

Numerical Analysis of Tunnel Excavation Method at Greatly Cross Undermine Huangzhuang Station of Beijing Subway

2011 ◽  
Vol 243-249 ◽  
pp. 5789-5793
Author(s):  
Jin Shui Xie ◽  
Ming Zhou Bai ◽  
Zhao Yi Xu ◽  
Ming Xing Xu ◽  
Zhu Shi ◽  
...  
Keyword(s):  
Numerical Calculation ◽  
Numerical Analysis ◽  
Surface Deformation ◽  
Ground Surface ◽  
Side Wall ◽  
Tunnel Construction ◽  
Tunnel Excavation ◽  
Geological Conditions ◽  
Numerical Calculation Method ◽  
Beijing Subway

Combined with the geological conditions and the project features, the selection problem of pilot tunnel construction method of Huangzhuang station is solved. Directing at the commonly used method including CD method, CRD method and double side wall pilot tunnel method, FLAC3D numerical calculation method is adapted to analysis and predict the ground surface deformation and supporting structure hand features. Through analyzing the size and law of surface settlement in this section, the feasibility and differences of these methods is concluded and analyzed. And finally an example is given.

Tunnel behaviour associated with the weak Alpine rock masses of the Driskos Twin Tunnel system, Egnatia Odos Highway

2013 ◽  
Vol 50 (1) ◽  
pp. 91-120 ◽  
Author(s):  
N. Vlachopoulos ◽  
M.S. Diederichs ◽  
V. Marinos ◽  
P. Marinos
Keyword(s):  
Numerical Models ◽  
Three Dimensional ◽  
Monitoring Data ◽  
Tunnel Construction ◽  
Weak Rock ◽  
Rock Masses ◽  
Tunnel Excavation ◽  
Twin Tunnel ◽  
Geological Conditions ◽  
Weak Rock Masses

Based on the excessive deformations and support failure encountered during tunnel construction at the Driskos Twin Tunnel site in Northern Greece, this paper provides insight on how tunnels designed in such weak rock environments can be realistically analyzed with a view of determining better analytical tools to predict deformations and improving current design methods. Specific factors that were assessed include rock strength based on the geological strength index (GSI), tunnel deformation, numerical analysis techniques employed, three-dimensional model type, support considerations, dilation, sequencing of tunnel excavation, influence of single bore construction on twin bore, and homogenization of tunnel faces. This work involves the use of nominally identical two- and three-dimensional numerical models of tunnel sequencing for analytical simulation of weak material behaviour and sequential tunnel deformation response with the goal of investigating the strength and deformation of such weak rock masses. These have been used in combination with monitoring data that were obtained in the field during the Driskos Twin Tunnel construction. A discussion of the geological conditions, material property determination, monitoring data, and model calibration strategy is given. This paper provides insight into these issues and poses many more fundamental questions regarding the analysis of tunnel excavation within weak rock masses requiring further investigation.

Metallogenic Geological Conditions and Prospecting Indicators of the Carbonate-Hosted Pb-Zn Deposits in Northeastern Yunnan Province, China

2014 ◽  
Vol 962-965 ◽  
pp. 296-299
Author(s):  
Guang Shu Yang ◽  
Yong Feng Yan ◽  
Peng Yu Feng ◽  
Jun Wei Zhang
Keyword(s):  
Large Scale ◽  
Yunnan Province ◽  
Thrust Fault ◽  
Geological Mapping ◽  
Forming Mechanism ◽  
Common Features ◽  
Geological Conditions ◽  
Ore Prospecting ◽  
Geochemical Studies ◽  
Northeastern Yunnan

Based on large scale geological mapping, geological-section, tectonic and geochemical studies on the carbonate-hosted Pb-Zn deposits in NE Yunnan, the metallogenic geological conditions are discussed, and the ore-prospecting indicators are summarized. The Pb-Zn deposits have many common features, which are mainly controlled by the thrust fault-fold structures and lithological conditions. The ore-forming mechanism of them is similar to the MVT Pb-Zn deposit. The combination of thrust fault-fold structures and altered carbonate rocks with geochemical anomalies are good indicators for prospecting.

scholarly journals Landslide Triggered by Orthogonal Tunnel Excavation and Prevention Measures in Jimei Village, Sichuan Province, China

2021 ◽  
Author(s):  
zhongfu wang ◽  
Han Dong Liu ◽  
Si Ming He ◽  
Yunfeng Fang
Keyword(s):  
Numerical Simulation ◽  
Interaction Mechanism ◽  
Tunnel Construction ◽  
Prevention Measures ◽  
Tunnel Excavation ◽  
Ancient Landslide ◽  
Site Monitoring ◽  
Geological Conditions ◽  
Landslide Deformation ◽  
The Stability

Abstract The axis of highway tunnels constructed in mountains under complex geological conditions is usually orthogonal to the section of potential landslide. The tunnel construction may lead to landslide, which then may result in the deformation and/or cracking of tunnels. Therefore, it is very important and practical for tunnel projects to study the complex interaction mechanism between orthogonal tunnel and landslide and provide appropriate prevention measures for tunnel. This paper, on the base of geological survey, on-site monitoring and numerical simulation, analyzed the deformation and reason of an ancient landslide revived by tunnel construction and studied the prevention measures for tunnel. The results show that the reason for the revival of the ancient landslide resulted mainly from the tunnel construction through sliding surface, and the ancient landslide is generally stable because most landslide deformation occurred beyond the tunnel and in the upper part of landslide. The numerical simulation was used to optimize the tunnel prevention scheme by the analysis to the stability, stresses and deformation of landslide based on stress-strain control theory. The original anti-slide pile design was cancelled and finally the tunnel is reinforced by upper soil removal and moving upper soil into toe. This tunnel has successfully completed and are under good operation. The used prevention measures were proven to be effective according to the monitoring data about displacements and stress of landslide and tunnel during operation period, and saved about seven million US$. The research results in this paper may offer a beneficial reference to projects with similar geological conditions.

Analysis and Control the Surface Settlement of Tunnel Excavation

2013 ◽  
Vol 438-439 ◽  
pp. 939-942
Author(s):  
Jing Jing Li ◽  
Hui Ren Bai ◽  
Jin Kui Li
Keyword(s):  
Settling Tank ◽  
Surface Subsidence ◽  
High Tech ◽  
Tunnel Construction ◽  
Tunnel Excavation ◽  
Deformation Control ◽  
Geological Conditions ◽  
Surface Subsidence Control ◽  
And Control ◽  
Technical Measures

Combined with the station of Maritime University ~ High-tech Zone tunnel project, this paper analyzes each section of the measured data on the spot to determine the surface subsidence. Research results show that the soil geological conditions of different effects on the subsidence are obvious, but shapes which formed by the settling tank are similar. Meanwhile, combining the construction of advanced small pipe grouting and shotcreting concrete technical measures, the surface subsidence control of the project abides by the surface subsidence rule of the shallow tunnel construction and deformation control.

scholarly journals Empirical analyses of excavation method and tunnel support system based on engineering geology of Tunnel No.8 at Jakarta – Bandung high-speed railway, West Bandung, Province of West Java, Indonesia

2021 ◽  
Vol 325 ◽  
pp. 01003
Author(s):  
Ika Medika Ayu Oktarina ◽  
Subagyo Pramumijoyo ◽  
I Gde Budi Indrawan
Keyword(s):  
Rock Mass ◽  
Support System ◽  
High Speed ◽  
Surface Engineering ◽  
Geological Mapping ◽  
Geological Strength Index ◽  
Tunnel Construction ◽  
High Speed Railway ◽  
Tunnel Support ◽  
Geological Conditions

The Chinese Basic Quality (BQ) system was used to determine the rock mass classes and design tunnel support system of the Tunnel No.8 of the Jakarta-Bandung high-speed railway. As the BQ system is newly applied for tunnelling project in Indonesia and remains poorly understood, this research aims to determine rock mass classes at the tunnel construction site and propose the tunnel excavation method and support system alternative based on more widely used rock mass classifications of the Geological Strength Index (GSI) and Japan Society of Civil Engineers (JSCE) standard. Surface engineering geological mapping and evaluation of drill core samples were carried out to obtain accurate interpretation of subsurface engineering geological conditions, particularly the rock mass classes at the tunnel elevation. The results show that the tunnel construction area consists of very poor to fair classes of andesite breccia, tuff lapilli, and tuffaceous sandstone. The full-face method with auxiliary bench cut and multiple-bench cut method are to be applied at the tunnel sections consisting of rock mass classes CI and DII, respectively. The proposed tunnel support system is a combination of shotcrete, rock bolt, steel rib, and invert.

scholarly journals One-dimensional constrained inversion study of TEM and application in coal goafs’ detection

2020 ◽  
Vol 12 (1) ◽  
pp. 1533-1540
Author(s):  
Si Yuanlei ◽  
Li Maofei ◽  
Liu Yaoning ◽  
Guo Weihong
Keyword(s):  
Least Squares ◽  
Least Squares Method ◽  
Data Interpretation ◽  
Volume Effect ◽  
Underground Space ◽  
Attenuation Curve ◽  
One Dimensional ◽  
Transient Electromagnetic ◽  
Geological Conditions ◽  
Geological Information

AbstractTransient electromagnetic method (TEM) is often used in urban underground space exploration and field geological resource detection. Inversion is the most important step in data interpretation. Because of the volume effect of the TEM, the inversion results are usually multi-solvable. To reduce the multi-solvability of inversion, the constrained inversion of TEM has been studied using the least squares method. The inversion trials were performed using two three-layer theoretical geological models and one four-layer theoretical geological model. The results show that one-dimensional least squares constrained inversion is faster and more effective than unconstrained inversion. The induced electromotive force attenuation curves of the inversion model indicate that the same attenuation curve may be used for different geological conditions. Therefore, constrained inversion using known geological information can more accurately reflect the underground geological information.

scholarly journals Numerical Modelling of The Behavior of Tunnel in Soft Surrounding Rock. A Case Study of Djebel El-Ouahch Tunnel, Algeria.

2021 ◽  
Author(s):  
Barkane Aicha ◽  
Sami Mezhoud
Keyword(s):  
Reference Model ◽  
Soil Behavior ◽  
Tunnel Excavation ◽  
Circular Section ◽  
Geological Conditions ◽  
The Stability ◽  
Tunnel Cross Section ◽  
Calculation Code ◽  
Surrounding Soil

Abstract The response of a massif to stresses generated by tunnel excavation depends essentially on the geological conditions, the geometry of the tunnel and its underground position. The major problem related to the construction of these structures is to ensure the stability of the whole tunnel-ground, by controlling the various deformation generated during the constructionIn this context, the present paper examines the effect of these conditions on the behavior of tunnels and the surrounding soil. The study is applied to a real tunnel, in this case the tunnel of Djebel El Ouahch, Algeria was taken as a reference model. The research includes a parametric study to evaluate the effect of several parameters on the behavior of the tunnel and surrounding soil such as the tunnel anchoring depth, the tunnel-soil interface rate, and the shape of the tunnel cross section. The analysis is performed using the PLAXIS 3D TUNNEL calculation code with an elastoplastic Mohr-coulomb model for the soil behavior. The results show that the strongest and most stable position is the mid-deep tunnel with a circular section, with a non-slip interface between the tunnel and the ground. These outcomes can help to understand the effects of various influences parameters which control the stability of the tunnel in a soil with bad characteristics.

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