Experimental Study on Deformation Properties of Lining Structure of Hydraulic Tunnel

2011 ◽  
Vol 105-107 ◽  
pp. 1320-1325
Author(s):  
Shi Lang Xu ◽  
Wei Shen
Keyword(s):  
Bearing Capacity ◽  
Water Pressure ◽  
Interaction Force ◽  
Surrounding Rock ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Water Seepage ◽  
Deformation Properties ◽  
Lining Structure ◽  
Stress And Deformation

A large-scale indoor model test with water pressure is conducted in order to investigate the stress and deformation properties of reinforced concrete lining structures with circular cross-sections. After lining structure cracks, the stress and deformation of reinforcement in lining structures tend to decrease. Although the interaction force between lining structure and surrounding rock increases with the increase of water pressure, but the ratio of interaction force and water pressure decreases, which reveals that the load-bearing capacity of lining structures decreases, and surrounding rock gradually performs as the primary load-bearing body. The internal water pressure carried by lining structure is about 20%~40% of water pressure before cracking and less than 30% after cracking. Test results illustrate that surrounding rock and inner water seepage significantly influence the stress and deformation properties of lining structure, and inner water seepage is the main reason for the reduction of load-bearing capacity of lining structures.

scholarly journals EXPERIMENTAL INVESTIGATION OF LOAD-BEARING CAPACITY AND DEFLECTIONS OF FULL-SCALE GLUED LAMINATED TIMBER BEAMS

2020 ◽  
Vol 2 (61) ◽  
pp. 5-11
Author(s):  
S. Shekhorkina ◽  
◽  
К. Shliakhov ◽  
А. Sopilniak ◽  
◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Strength Class ◽  
Failure Load ◽  
Timber Structures ◽  
Load Bearing Capacity ◽  
Concentrated Load ◽  
Load Bearing ◽  
Glued Laminated Timber ◽  
Deformation Properties ◽  
Timber Beams

With the transition to the design of timber structures in accordance with European standards, problems arise in assessment of the load-bearing capacity of glued timber structures that are caused by insufficient amount of data about the physical, mechanical and deformation properties of glued timber, which is produced in Ukraine. The aim of the work was to determine the load bearing capacity in bending and deflection of a glued timber beam under the action of a concentrated load in the middle of the span. Two glued laminated timber beams were used in the experiment. Both beams were made using lumber from pine wood and a moisture-curing onecomponent polyurethane adhesive Kleiberit PUR 510 FiberBond. The beams have the dimensions of the cross-section: width of 120 mm and height of 180 mm. The length of the beams was 9880 mm. Each beam consisted of 9 layers of 20 mm thick lamellas glued together. Considering the absence of the data on the strength class of the beam material, the theoretical load bearing capacity and deflection were determined according to the characteristics of the GL24h class (minimum strength class), and amounted to 722 kgf and 19.1 cm, respectively. As a result of the tests, the failure load and the deflection of the beams were determined, and the dependences of the deflection on the load were obtained. The actual deflection of the beams determined was 251 mm and 275 mm, which is 1.31 and 1.44 times higher than the predicted deflection. Accordingly, the failure load determined experimentally is 1.96 and 2.03 times higher than the theoretical value. During the tests, the features of the deformation and the nature of the destruction of the beams were investigated. Wherein, the determining factor was the presence of defects in timber and lamellas joints along the length in the most stressed layers. Based on the data obtained, recommendations on manufacturing aimed at the increasing the bending strength of glued laminated timber beams are given. The results obtained will be further used in the development of structural solutions for hybrid timber-concrete floors.

Loading Tests of Experimental Models of an Integral Bridge Loaded by the Effects of Water Pressure during Floods

2014 ◽  
Vol 587-589 ◽  
pp. 1554-1557
Author(s):  
Petr Tej ◽  
Jiří Kolísko ◽  
Petr Bouška ◽  
Miroslav Vokáč ◽  
Tomáš Bittner ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Computer Simulations ◽  
Water Pressure ◽  
Experimental Models ◽  
Bridge Structure ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Integral Bridge ◽  
Horizontal Pressure ◽  
Loading Tests

This paper presents an experimental and computer analysis of an integral bridge structure exposed to a load caused by the horizontal pressure of water during floods. The paper focuses on the residual load-bearing capacity of an integral bridge structure that was able to withstand the effects of flooding. ​​Three models of integral bridges built to a scale of 1:5 were made for the purpose of testing. The frames have a span of 2.6 m, the thickness of the supports is 0.2 m, and the thickness of the deck in the middle is 0.125 m. The frames are loaded by horizontal forces representing the water pressure during floods. Each frame is securely anchored at the base and is gradually loaded by two horizontal forces situated in the corners of the frame. Loading is interrupted when cracks of 0.3 mm appear. Subsequently, the frame is loaded by a pair of vertical forces acting on the top surface of the frame, up to the load-bearing capacity. This procedure was established in order to find the residual load-bearing capacity of an integral bridge that managed to withstand the effects of flooding. . The paper includes a set of computer simulations.

scholarly journals A comparison between performances of the behavioral models in evaluating load-bearing capacity of piles in fine-grained unsaturated soil

2018 ◽  
Vol 8 (1) ◽  
pp. 233-239
Author(s):  
Omid Bandehzadeh ◽  
Masoud Mirmohammad Sadeghi ◽  
Mohammad Ali Rowshanzamir ◽  
Alborz Hajian Nia
Keyword(s):  
Bearing Capacity ◽  
Unsaturated Soil ◽  
Unsaturated Soils ◽  
Load Capacity ◽  
Water Pressure ◽  
Behavioral Models ◽  
Load Bearing Capacity ◽  
Static State ◽  
Load Bearing ◽  
Modified Cam Clay

<p>Virtually all structural piles are installed on the top of groundwater level, and these piles are located on unsaturated soils. In this case, the negative orifice water pressure caused by capillarity significantly influences the mechanical behavior of unsaturated soils. Consequently, structural suction is highly important to load-bearing capacity of loads. In this paper, an evaluation was drawn between the Mohr-Coulomb, modified Cam-Clay, and Barcelona behavioral models using the finite-difference method, and results of studies conducted to estimate load-bearing capacity in the static state were provided. The behavioral model guidelines matched the laboratory models. To estimate soil vividness on the suction level of concern, the water-soil curve (showing suction patterns in relation to moisture) utilized. The general tendencies of settlement gotten by the numerical examination are reliable with pile insert test results. Results suggest that the Barcelona personality model (BBM) yields more realistic estimates of load capacity as it looks at the effect of unsaturated soil suction.</p>

scholarly journals Experimental research on the haulage drifts stability in steeply dipping seams

2021 ◽  
Vol 15 (4) ◽  
pp. 56-67
Author(s):  
Ihor Iordanov ◽  
Ihor Buleha ◽  
Yaroslava Bachurina ◽  
Hennadii Boichenko ◽  
Vitaliy Dovgal ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Mine Working ◽  
Experimental Studies ◽  
Load Bearing Capacity ◽  
Mining Site ◽  
Load Bearing ◽  
Deformation Properties ◽  
Mine Workings ◽  
Coal Pillars ◽  
Protective Structures

Purpose. Substantiation of the conditions for haulage drifts stability using different protection methods in steeply dipping seams based on a set of experimental studies. Methods. To achieve the purpose set, mine instrumental observations have been performed to study the rock pressure manifestations in zonal advance workings adjacent to the stope face on the haulage horizon. The conditions for their maintenance, within the mining site, are assessed by the side rocks convergence value on the drift contour and the change in the cross-sectional area, taking into account the deformation properties of the protective structures. Findings. It is recorded that in the zone of the stope works influence, in the most difficult conditions, haulage drifts are maintained, when coal pillars or clumps of prop stays are used for their protection. It has been determined that a decrease in the section of such mine workings up to 50% is the result of the protective structures destruction. When protecting the hau-lage drifts with the rolling-on chocks, a decrease in the mine working section up to 30% occurs in the process of the protective structures compression. It has been revealed that deformation of coal pillars or clumps of prop stays up to 10-20% leads to a loss of their stability, and an increase to 60% leads to a complete loss of their load-bearing capacity, intensification of rock displacements on the mine working contour and deterioration of its stability. It has been determined that in the process of deformation of the rolling-on chocks from sleepers by 20-60%, they are compressed without loss of load-bearing capacity, which ensures a smooth deflection of the overhanging stratum and restriction of rock displacements on the haulage drift contour. Originality. To study the deformation characteristics of protective structures above the drift, the function of the increment is used of side rock displacements on the haulage drift contour along the mining site length dependent on the relative deformations of protective structures, which makes it possible to assess the real dynamics of the process. Practical implications. When mining steep coal seams, using the specificity of geomechanical processes, which are manifested in an anisotropic coal-rock mass during unloading, satisfactory mine workings stability can be ensured by changing the deformation properties of protective structures above the drift.

Experimental Study on the Carrying Capacity of Lining Structure of Hydraulic Tunnel

2011 ◽  
Vol 361-363 ◽  
pp. 1593-1597
Author(s):  
Wei Shen ◽  
Shi Lang Xu
Keyword(s):  
Large Scale ◽  
Water Pressure ◽  
Concrete Lining ◽  
Outer Side ◽  
Total Water ◽  
Deformation Properties ◽  
Lining Structure ◽  
External Water Pressure ◽  
External Water ◽  
Stress And Deformation

In this paper, a large-scale indoor model test with water pressure is conducted in order to investigate the stress and deformation properties of reinforced concrete lining structures with circular cross-sections.Under internal water pressure, the water pressure carried by lining structure is about 20%~40% of total water pressure before cracking and less than 30% after cracking.Under external water pressure, without drainage of outer side of lining, the water pressure carried by lining structure is only less than 40% of total water pressure.

Increased load bearing capacity of mechanically joined FRP/metal joints using a pin structured auxiliary joining element

2020 ◽  
Vol 62 (1) ◽  
pp. 55-60
Author(s):  
Per Heyser ◽  
Vadim Sartisson ◽  
Gerson Meschut ◽  
Marcel Droß ◽  
Klaus Dröder
Keyword(s):  
Bearing Capacity ◽  
Load Bearing Capacity ◽  
Load Bearing

Load-Bearing Capacity of Direct Inlay-Retained Fibre-reinforced Composite Fixed Partial Dentures with Different Cross-Sectional Pontic Design

2017 ◽  
Vol 68 (1) ◽  
pp. 94-100
Author(s):  
Oana Tanculescu ◽  
Adrian Doloca ◽  
Raluca Maria Vieriu ◽  
Florentina Mocanu ◽  
Gabriela Ifteni ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Fracture Pattern ◽  
Load Bearing Capacity ◽  
Cross Sectional ◽  
Load Bearing ◽  
Reinforced Composite ◽  
Polyethylene Fibre

The load-bearing capacity and fracture pattern of direct inlay-retained FRC FDPs with two different cross-sectional designs of the ponticwere tested. The aim of the study was to evaluate a new fibre disposition. Two types of composites, Filtek Bulk Fill Posterior Restorative and Filtek Z250 (3M/ESPE, St. Paul, MN, USA), and one braided polyethylene fibre, Construct (Kerr, USA) were used. The results of the study suggested that the new tested disposition of the fibres prevented in some extend the delamination of the composite on buccal and facial sides of the pontic and increased the load-bearing capacity of the bridges.

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