Analysis of extruded concrete lining tunnel by FEM

2019 ◽  
pp. 185-196
Author(s):  
M.C.W. Kimenai ◽  
F.J.M. Hoefsloot
Keyword(s):  
Concrete Lining

Low Alkaline Cement Used in the Construction of a Gallery in the Horonobe Underground Research Laboratory

2010 ◽  
Author(s):  
Masashi Nakayama ◽  
Haruo Sato ◽  
Yutaka Sugita ◽  
Seiji Ito ◽  
Masashi Minamide ◽  
...  
Keyword(s):  
Fly Ash ◽  
Research Laboratory ◽  
Concrete Lining ◽  
Energy Agency ◽  
Tunnel Support ◽  
Long Term Stability ◽  
Alkaline Conditions ◽  
High Level ◽  
Underground Research Laboratory

In Japan, any high level radioactive waste (HLW) repository is to be constructed at over 300 m depth below surface. Tunnel support is used for safety during the construction and operation, and shotcrete and concrete lining are used as the tunnel support. Concrete is a composite material comprised of aggregate, cement and various admixtures. Low alkaline cement has been developed for the long term stability of the barrier systems whose performance could be negatively affected by highly alkaline conditions arising due to cement used in a repository. Japan Atomic Energy Agency (JAEA) has developed a low alkaline cement, named as HFSC (Highly Fly-ash Contained Silicafume Cement), containing over 60 wt% of silica-fume (SF) and fly-ash (FA). HFSC was used experimentally as the shotcrete material in construction of part of the 140m deep gallery in the Horonobe Underground Research Laboratory (URL). The objective of this experiment was to assess the performance of HFSC shotcrete in terms of mechanics, workability, durability, and so on. HFSC used in this experiment is composed of 40 wt% OPC (Ordinary Portland Cement), 20 wt% SF, and 40 wt% FA. This composition was determined based on mechanical testing of various mixes of the above components. Because of the low OPC content, the strength of HFSC tends to be lower than that of OPC. The total length of tunnel using HFSC shotcrete is about 73 m and about 500 m3 of HFSC was used. The workability of HFSC shotcrete was confirmed in this experimental construction.

Construction and operation of batching plants in difficult geological conditions of Upper Kama potash mines

2021 ◽  
pp. 51-56
Author(s):  
V. N. Aptukov ◽  
V. V. Tarasov ◽  
V. S. Pestrikova ◽  
O. V. Ivanov
Keyword(s):  
Crack Opening ◽  
Concrete Lining ◽  
Salt Deposit ◽  
Mine Shaft ◽  
Deformation And Fracture ◽  
Geological Conditions ◽  
Negative Impacts ◽  
Long Term Experience ◽  
Term Maintenance

Scenarios of the component arrangement of batching plants in the system of a vertical mine shaft are discussed. The features of operation of batching plants in vertical shafts of potash mines are identified. The actual recorded damages generated in the lining of batching plants in the course of their longterm operation in potash mines are described. The geomechanical researches aimed to determine vertical convergence in batching rooms of mine shafts, as well as for monitoring of crack opening and displacements in sidewalls in the batching chambers are presented. The major results of the full-scale geomechanical observations are reported, and the main causes of fractures in concrete and reinforced concrete lining at junctures of shafts and batching rooms and shaft bins are identified. The set of the engineering solutions implemented for the protection of lining in batching facilities during construction of mine shafts is described, and its efficiency is evaluated. The mathematical modeling is carried out to estimate various negative impacts on deformation and fracture of concrete lining in shafts with regard to the time factor. From the modeling results, the dominant cause of concrete lining damage in batching chambers and in mine shaft is found. Based on the accomplished research results and actual long-term experience of operation of mine shafts, the most favorable factors are determined for the best design choices in construction and long-term maintenance-free operation of batching plants in potash mines of the Upper Kama Potash–Magnesium Salt Deposit.

Displacements in the Claremont Water Tunnel at the intersection with the Hayward fault

1966 ◽  
Vol 56 (2) ◽  
pp. 291-294
Author(s):  
F. B. Blanchard ◽  
G. L. Laverty
Keyword(s):  
Fault Zone ◽  
Concrete Lining ◽  
Water Tunnel ◽  
Point Of Intersection

abstract Three cracks have been observed in the concrete lining of the Claremont Water Tunnel at its point of intersection with the Hayward fault zone. The cracks, which show a right-lateral sense of displacement, were not present fourteen years ago in 1950.

Fuzzy Matter-Element Evaluation Method for Reliability Analysis of an Existing Highway Tunnel

2010 ◽  
Vol 163-167 ◽  
pp. 3110-3113
Author(s):  
Zheng Xi Gong ◽  
Jian Guo Yang
Keyword(s):  
Reliability Analysis ◽  
Evaluation Method ◽  
Evaluation Model ◽  
Concrete Strength ◽  
Concrete Lining ◽  
Tunnel Structure ◽  
Entropy Weight ◽  
Element Analysis ◽  
Evaluation Indexes ◽  
Highway Tunnel

Reliability analysis is the premise for reinforcement and maintenance of an existing highway tunnel. In order to understand the structure reliability of an existing highway tunnel, a fuzzy mat-ter-element evaluation method was put forward based on entropy weight according to the fuzzy matter-element analysis method. Firstly, levels of inspection results were regarded as objects of matter-element and composite fuzzy matter-elements were constructed considering such factors and their evaluation indexes as cracks of concrete lining, lining thickness, concrete strength, cavities behind the lining and water leakage conditions. Secondly, reliability evaluation results of the existing tunnel structure were obtained by calculating the relevancy. Lastly, fuzzy matter-element evaluation model was effectively used to evaluate reliability of one highway tunnel structure.

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