Study of Control Empty Width in the Underground Penstock Contact Grouting Engineering

2014 ◽  
Vol 638-640 ◽  
pp. 829-836
Author(s):  
Yan Shen ◽  
Yan Ni Shao ◽  
Xiao Li ◽  
Hui Ping Wang
Keyword(s):  
Surrounding Rock ◽  
Contact Element ◽  
Steel Pipe ◽  
Running Safety ◽  
Steel Lining ◽  
Operation Process ◽  
Empty Area

Determining control empty size can be used as a standard of deciding whether contact grouting in the empty area is needed, in order to reduce the construction difficulty and enhance running safety of underground penstock. In this paper, underground penstock operation process has been simulated by means of the well-known FEA software-ANSYS. The empty conditions and joint bearing of steel lining and surrounding rock have been simulated by setting contact element. In this way, control empty width of different radius steel pipe and different initial gap has been calculated. The result provides reference to decide whether contact grouting between steel lining and back filled concrete needed.

Application of Concrete Filled Steel Tubular Supports in the Shaft Station

2015 ◽  
Vol 1089 ◽  
pp. 213-218
Author(s):  
Hao Xie ◽  
Feng Yin Zhang ◽  
He Guo ◽  
Bao Sen Zhang
Keyword(s):  
Large Deformation ◽  
Cross Section ◽  
Coal Mine ◽  
Surrounding Rock ◽  
Steel Pipe ◽  
Long Term Stability ◽  
Field Investigations ◽  
Grouting Reinforcement ◽  
Seamless Steel

In order to solve the issues of large deformation and difficult to support in Lu Cun coal mine-270m level shaft station, the reasons of damage to the original roadway supporting conditions have been analyzed through the field investigations. A composite supporting scheme which depend mostly on concrete-filled steel tubular (CFST) supports, spray the anchor net and surrounding rock grouting reinforcement technology as a supplement was designed. The cross-section of the supports is circular. The main steel pipe is 20# seamless steel pipe with diameter of 194mm and wall thickness of 8mm. It is shows that the composite supports can effectively control the deformation of surrounding rock of roadway and maintain long-term stability.

Dynamical Response of Circular Tunnel with Steel Lining under the Action of Blasting Vibration

2010 ◽  
Vol 163-167 ◽  
pp. 4037-4042 ◽  
Author(s):  
Chang Ping Yi ◽  
Wen Bo Lu ◽  
Ling Feng ◽  
Gang Wang
Keyword(s):  
Rock Mass ◽  
Velocity Distribution ◽  
Expansion Method ◽  
Surrounding Rock ◽  
Vibration Velocity ◽  
Dynamical Response ◽  
Blasting Vibration ◽  
Circular Tunnel ◽  
Steel Lining ◽  
Wave Function Expansion Method

The wave function expansion method is used to analyze the interaction process of the blasting seismic wave and the adjacent circular tunnel with steel lining, the stress expression, displacement expression and vibration velocity expression of circular tunnel under the action of blasting vibration are deduced, the stress, displacement and vibration velocity distribution of surrounding rock mass and steel lining are presented under the definite condition. In terms of the stress and vibration velocity distribution and the tensile strength of the rock mass, the critical failure vibration velocity of surrounding rock mass is obtained.

scholarly journals Novel Segmented Roadside Plugging-Filling Mining Method and Overlying Rock Mechanical Mechanism Analyses

Energies ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 2073 ◽  
Author(s):  
Wenqiang Mu ◽  
Lianchong Li ◽  
Zhongping Guo ◽  
Zhaowen Du ◽  
Sixu Wang
Keyword(s):  
Coal Mining ◽  
Surrounding Rock ◽  
Equivalent Model ◽  
Mine Pressure ◽  
Mining Method ◽  
Operation Process ◽  
Geological Conditions ◽  
Pillar Mining ◽  
The Stability ◽  
Site Test

The no-pillar mining method is widely used in coal mining engineering because of its superiority in resolving mine pressure hazards and protecting natural resources. In view of the geological conditions of stable strata in a coal mine of the Shandong Coal Zone, a novel segmented roadside plugging-filling mining method is proposed by introducing the filling coefficient into roadside filling. The operation process is designed with a new grouting filling forming device. Based on the relationship between the theoretical deflection of a cantilever beam and geometric settlement and parallel settlement models, strength formulas applicable to the segmented roadside plugging-filling (SRPF) method at different migration stages are obtained, and the deformation formulas of a roadway toward a rock slab are solved by an elastic equivalent model. Further, the determination procedure of the filling mode under the mining method is clarified. The SRPF method was implemented on a test stope, and the test results indicated that the theoretical deformation produced by the SRPF method was small and can meet the mining requirements. Through on-site test monitoring, the deformation of surrounding rock was 0–160 mm and the filling body under the SRPF method could maintain its own strength and the stability of the surrounding rock. In addition, entire successful mining been completed in the working stope, which further proves the applicability of this method. The backfilling cost of the gob-side filling was reduced by approximately 50%, and the backfilling efficiency was improved in the mine. The description of the novel mining method may provide theoretical and practical guidance for coal mining in similar geological conditions.

Bearing Behavior of Steel Foot Pipe in Tunnel on Soft Base

2010 ◽  
Vol 163-167 ◽  
pp. 3604-3609
Author(s):  
Yi Min Wu
Keyword(s):  
Numerical Simulations ◽  
Bearing Capacity ◽  
Influencing Factors ◽  
Surrounding Rock ◽  
Steel Pipe ◽  
Geological Condition ◽  
Lateral Zone ◽  
Maximal Stress ◽  
Dip Angle ◽  
Bearing Behavior

Numerical simulations were conducted to investigate the bearing behaviour of steel foot pipe. Main mechanical affections occur at the lateral zone, and the maximal stress occurs at the lateral end of the pipe. With the increase of cross direction load, the maximal stress increases and exceeds the strength of material, and the pipe is pulled out. The influencing factors of bearing capacity of the steel foot pipe were studied. Some important results different from engineering experiences are as following: 1) to steel foot pipe that can not penetrate the soft base, its reasonable dip angle is very small for its low longitudinal bearing capacity; 2) steel pipe with diameter of 42mm is unsuitable for foot steel pipe because its low cross bearing capacity; 3) to a given geological condition and pipe parameter, the reasonable length of steel pipe is certain, extra longer pipes can’t obtain larger capacity; 4) surrounding rock near the support structure should be especially reinforced by drilling grouting holes along the whole steel pipe.

A study on Evaluation of running safety of Increasing Speed Vehicle·track in Turnout Rigid Crossing

2017 ◽  
Vol 5 (3) ◽  
pp. 859-865
Author(s):  
Se-gon Kwon ◽  
Jong-min Seo ◽  
Yong-ju Park ◽  
Sung-back Park
Keyword(s):  
Running Safety

Influence exerted by underground excavation shape and by effective stresses on the formation of a tensile strain zone at a depth greater than 1 km

2020 ◽  
pp. 67-75
Author(s):  
Van Min Nguyen ◽  
V. A. Eremenko ◽  
M. A. Sukhorukova ◽  
S. S. Shermatova
Keyword(s):  
Rock Mass ◽  
Cross Sections ◽  
Tensile Strain ◽  
Rock Fracture ◽  
Strain Analysis ◽  
Surrounding Rock ◽  
Underground Excavation ◽  
Secondary Stress ◽  
Principal Stresses ◽  
Mining Depth

The article presents the studies into the secondary stress field formed in surrounding rock mass around underground excavations of different cross-sections and the variants of principal stresses at a mining depth greater than 1 km. The stress-strain analysis of surrounding rock mass around development headings was performed in Map3D environment. The obtained results of the quantitative analysis are currently used in adjustment of the model over the whole period of heading and support of operating mine openings. The estimates of the assumed parameters of excavations, as well as the calculations of micro-strains in surrounding rock mass by three scenarios are given. During heading in the test area in granite, dense fracturing and formation of tensile strain zone proceeds from the boundary of e ≥ 350me and is used to determine rough distances from the roof ( H roof) and sidewalls ( H side) of an underground excavation to the 3 boundary e = 350me (probable rock fracture zone). The modeling has determined the structure of secondary stress and strain fields in the conditions of heading operations at great depths.

DEFLAGRATION-TO-DETONATION TRANSITION IN A STRATIFIED SYSTEM “GASEOUS OXYGEN-LIQUID FILM OF N-DECANE”

2020 ◽  
Author(s):  
S. M. FROLOV ◽  
◽  
V. S. AKSENOV ◽  
I. O. SHAMSHIN ◽  
◽  
...  
Keyword(s):  
Liquid Film ◽  
Ignition Source ◽  
Gaseous Oxygen ◽  
Deflagration To Detonation Transition ◽  
Operation Process ◽  
Continuous Detonation ◽  
Smooth Channel ◽  
Detonation Transition ◽  
Run Up ◽  
X 24

Deflagration-to-detonation transition (DDT) in the system “gaseous oxygen- liquid film of n-decane” ' with a weak ignition source was obtained experimentally. In a series of experiments with ignition by an exploding wire that generates a weak primary shock wave (SW) with a Mach number ranging from 1.03 to 1.4, the DDT with the detonation run-up distances 1 to 4 m from the ignition source and run-up time 3 ms to 1.7 s after ignition was observed in a straight smooth channel of rectangular 54 x 24-millimeter cross section, 3 and 6 m in length with one open end. The DDT is obtained for relatively thick films with a thickness of 0. 3-0.5 mm, which corresponds to very high values of the overall fuel-to-oxygen equivalence ratios of 20-40. The registered velocity of the detonation wave (DW) was 1400-1700 m/s. In a number of experiments, a high-velocity quasi-stationary detonation-like combustion front was recorded running at an average velocity of 700-1100 m/s. Its structure includes the leading SW followed by the reaction zone with a time delay of 90 to 190 s. The obtained results are important for the organization of the operation process in advanced continuous-detonation and pulsed-detonation combustors of rocket and air-breathing engines with the supply of liquid fuel in the form of a wall film.

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