scholarly journals Design and technological parameters of equipment influence on the lateral pressure coefficient and reduced friction coefficient of granular polyvinyl chloride

2021 ◽  
Vol 10 (1) ◽  
pp. 182-197
Author(s):  
Viktor Vytvytskyi ◽  
Ihor Mikulionok ◽  
Oleksandr Sokolskyi ◽  
Oleksandr Gavva ◽  
Liudmyla Kryvoplias-Volodina
Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4773
Author(s):  
Jianyu Li ◽  
Hong Li ◽  
Zheming Zhu ◽  
Ye Tao ◽  
Chun’an Tang

Geothermal power is being regarded as depending on techniques derived from hydrocarbon production in worldwide current strategy. However, it has artificially been developed far less than its natural potentials due to technical restrictions. This paper introduces the Enhanced Geothermal System based on Excavation (EGS-E), which is an innovative scheme of geothermal energy extraction. Then, based on cohesion-weakening-friction-strengthening model (CWFS) and literature investigation of granite test at high temperature, the initiation, propagation of excavation damaged zones (EDZs) under unloading and the EDZs scale in EGS-E closed to hydrostatic pressure state is studied. Finally, we have a discussion about the further evolution of surrounding rock stress and EDZs during ventilation is studied by thermal-mechanical coupling. The results show that the influence of high temperature damage on the mechanical parameters of granite should be considered; Lateral pressure coefficient affects the fracture morphology and scale of tunnel surrounding rock, and EDZs area is larger when the lateral pressure coefficient is 1.0 or 1.2; Ventilation of high temperature and high in-situ stress tunnel have a significant effect on the EDZs scale; Additional tensile stress is generated in the shallow of tunnel surrounding rock, and the compressive stress concentration transfers to the deep. EDZs experiences three expansion stages of slow, rapid and deceleration with cooling time, and the thermal insulation layer prolongs the slow growth stage.


1974 ◽  
Vol 8 (8) ◽  
pp. 496-499
Author(s):  
V. A. Belousov ◽  
�. �. Kol'man-Ivanov ◽  
I. E. Semenov-Ezhov ◽  
N. A. Stepanov ◽  
I. P. Sukharev

2018 ◽  
Vol 175 ◽  
pp. 03025
Author(s):  
Feng Zhou ◽  
Hongjian Jiang ◽  
Xiaorui Wang

The problem about the stability of tunnel surrounding rock is always an important research object of geotechnical engineering, and the right or wrong of the result from stability analysis on surrounding rock is related to success or failure of an underground project. In order to study the deformation rules of weak surrounding rock along with lateral pressure coefficient and burying depth varying under high geostress and discuss the dynamic variation trend of surrounding rock, the paper based on the application of finite difference software of FLAC3D, which can describe large deformation character of rock mass, analog simulation analysis of surrounding rock typical section of the class II was proceeded. Some conclusions were drawn as follows: (1) when burying depth is invariable, the displacements of tunnel surrounding rock have a trend of increasing first and then decreasing along with increasing of lateral pressure coefficient. The floor heave is the most sensitive to change of lateral pressure coefficient. The horizontal convergence takes second place. The vault subsidence is feeblish to change of lateral pressure coefficient. (2) The displacements of tunnel surrounding rock have some extend increase along with increasing of burying depth. The research conclusions are very effective in analyzing the stability of surrounding rock of Yunling tunnel. These are going to be a reference to tunnel supporting design and construction.


2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Peng Wu ◽  
Yanlong Chen ◽  
Liang Chen ◽  
Xianbiao Mao ◽  
Wei Zhang

Based on the Mohr–Coulomb criterion, a new analytical solution of a circular opening under nonuniform pressure was presented, which considered rock dilatancy effect and elastic-brittle-plastic failure characteristics. In the plastic zone, the attenuation of Young’s modulus was considered using a radius-dependent model (RDM), and solution of the radius and radial displacement of plastic zone was obtained. The results show that many factors have important impact on the response of the surrounding rock, including lateral pressure coefficient, dilation coefficient, buried depth, and Young’s modulus attenuation. Under nonuniform pressure condition, the distribution of plastic zone and deformation around the opening show obvious nonuniform characteristic: with the increasing of lateral pressure coefficient, the range of plastic zone and deformation decrease gradually at side, while they increase at roof and floor, and the location of the maximum value of support and surrounding rock response curve transfers from side to roof. Based on the analytical results and engineering practice, an optimization method of support design was proposed for the circular opening under nonuniform pressure.


2013 ◽  
Vol 353-356 ◽  
pp. 1515-1518
Author(s):  
Zhen Wang ◽  
Chun Han

The safety response of joint rock underground tunnels is one of the many problems that draw the attention of geology specialists and scholars. Adopting two dimensional discrete element method, a numerical model of joint rock underground cavern is established to study its stability. The buried depth and the lateral pressure coefficient are considered respectively. The result shows: when the lateral pressure coefficient is identical, the depth is bigger the displacement is more bigger, and the displacement is strong influenced by the buried depth when the lateral pressure coefficient is big; In the same depth the tunnel is buried, the tunnel rocks displacement is slightly influenced by the lateral pressure coefficient when it is small, but the influence is seriously as the lateral pressure coefficient is big. The simulation in the context can be used to provide guide for joint rock tunnel excavation and supporting.


2015 ◽  
Vol 741 ◽  
pp. 138-142 ◽  
Author(s):  
Feng Hai Ma ◽  
Yan Wang ◽  
Zhi Bin Wang

Internal force and deformation of surrounding rock and supporting structure of the nonlinear research is the use of finite element software ADINA by ideal elastic-plastic constitutive model.Results show that the lateral pressure coefficient increased from 0 to 1, and even decrease sharply arch sedimentation of surrounding rock, side wall horizontal displacement towards the hole along the radial direction development gradually reduced to 0 and reverse to the hole, when the lateral pressure coefficient is less than 0.5, bolt axial force biggest change is not obvious, when lambda increases gradually, the largest bolt axial force significantly increased.


2021 ◽  
Vol 12 (1) ◽  
pp. 57-71
Author(s):  
O. A Bogomolova

The results of computer modeling of the process of formation and development of areas of plastic deformations in the connected base of a double-slit ribbon foundation are presented. All calculations are performed using computer programs developed with the participation of the author. These programs allow you to take into account all the variety of physical and mechanical properties of the foundation soil (volume weight, internal friction angle, specific adhesion, lateral pressure coefficient and deformation modulus) and the foundation material (elastic modulus and Poisson's ratio). In the calculations, it is assumed that the value of the lateral pressure coefficient of the soil is 0.75, as is typical for cohesive clay soils, and the same value for the foundation material is assumed to be 0.43 (converted through the Poisson's ratio). Based on the results of calculations, it was possible to determine the features of the stress state of the base of the double-slit foundation and the process of development of plastic areas in the core of the foundation. First of all, the part of the bearing capacity of the base of the double-slit foundation that contacts its side surface is realized, and the inclusion of the side surface of the slit foundation in the work occurs from the bottom up. Then the part of the base that is located directly under the soles of the walls in the ground (cracks) is included in the work. It is established that the smaller the distance between the slits, the greater the bearing capacity of the base and the greater its part falls on the side surface. The bearing capacity of the base of a double-slit foundation is directly proportional to the depth of its foundation (the height of the cracks). The part of the load-bearing capacity realized on the side surface of the foundation can reach 60 % or more of its full value. An engineering method for calculating the load-bearing capacity of the base of a double-slit foundation, including simple formulas and graphs, is proposed. The method is formalized in a calculator program. The verification calculations showed a high degree of accuracy in approximating the results of the numerical experiment.


2011 ◽  
Vol 261-263 ◽  
pp. 1044-1048
Author(s):  
Yun Xiang He ◽  
Heng Bin Wu

The ground-liner interaction research has important engineering value for the underground engineering design optimization and evaluation of construction safety. The interface between ground and liner is considered. In this paper, the effect of different ground-liner stiffness ratio, lateral pressure coefficient, thickness and different interface stiffness ratio and other factors on the support structure for internal forces and interface stress is analyzed. The analysis results show that liner internal force and interface stress increase with the increase of stiffness ratio between liner and ground, and the impact is very significant. Effect of lateral pressure coefficient on liner internal force and interface stress mainly reflects on laws around the cavern, where 1 is the limitation of lateral pressure coefficient. It presents symmetrical distribution. With the increase of liner thickness, the liner internal force and interface normal stress increase, but it make no difference to the contact interface tangential stress.


Sign in / Sign up

Export Citation Format

Share Document