scholarly journals STUDY OF THE NATURE OF THE WORK OF PILES WITH ROTARY ANCHORS WHEN WORKING IN AN ARRAY OF HEAVING SOILS

2020 ◽  
Vol 11 (4) ◽  
pp. 46-57
Author(s):  
O. V Kostina ◽  
T. M Bochkareva
Keyword(s):  
Bearing Capacity ◽  
Design Solution ◽  
Test Results ◽  
Frost Heaving ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Main Pipelines

A new design of horizontal pivoting pile anchors used as supports for main pipelines on heaving and watered bases is proposed. The purpose of the design is to reduce the deformability of this type of Foundation and increase its load-bearing capacity under the influence of the forces of frost heaving of the soil. Stamp tests of models of piles with rotary anchors were performed on the stand for testing Foundation models of NPP GEOTECH. Based on the test results, the effectiveness of using piles with the location of their rotary anchors at one and two levels along the trunk was compared, and the reduction in the load-bearing capacity of the pile with an unfavorable location of the anchors was determined. It is shown that according to the results of stamp tests, the rotary anchors of piles positively affect the operation of the Foundation. The use of rotary anchors in one level increases the load-bearing capacity of the pile by 16 % and reduces shrinkage by 40 % compared to a pile of the same size, but without anchors. The use of anchors in two levels increases the load-bearing capacity of the pile by 73 % and reduces the draft by 48 %. The advantage of a pile with two levels of anchors compared to its own with one level of anchors is 48 % in terms of load-bearing capacity and 11 % in terms of draft. The use of rotary pile anchors can significantly increase the reliability of the foundations of main pipelines on heaving and watered bases. This design solution is more efficient than similar metal piles with vertical anchors at equal cost levels.

scholarly journals Tests and Analyses of Slotted-In Steel-Plate Connections in Composite Timber Shear Wall Panels

2017 ◽  
Vol 2017 ◽  
pp. 1-20
Author(s):  
Ulf Arne Girhammar ◽  
Bo Källsner
Keyword(s):  
Bearing Capacity ◽  
Failure Modes ◽  
Design Method ◽  
Shear Walls ◽  
Test Results ◽  
Horizontal Shear ◽  
Load Bearing Capacity ◽  
Wood Panel ◽  
Load Bearing ◽  
Plate Connections

The authors present an experimental and analytical study of slotted-in connections for joining walls in the Masonite flexible building (MFB) system. These connections are used for splicing wall elements and for tying down uplifting forces and resisting horizontal shear forces in stabilizing walls. The connection plates are inserted in a perimeter slot in the PlyBoard™ panel (a composite laminated wood panel) and fixed mechanically with screw fasteners. The load-bearing capacity of the slotted-in connection is determined experimentally and derived analytically for different failure modes. The test results show ductile postpeak load-slip characteristics, indicating that a plastic design method can be applied to calculate the horizontal load-bearing capacity of this type of shear walls.

Assesment of Main Models for Predicting Debonding Load-Bearing Capacity against Intermediate Crack-Induced Debonding Failure in FRP-Strengthened RC Beams

2011 ◽  
Vol 311-313 ◽  
pp. 1941-1944
Author(s):  
Gui Bing Li ◽  
Yu Gang Guo ◽  
Xiao Yan Sun
Keyword(s):  
Bearing Capacity ◽  
Failure Mode ◽  
Failure Modes ◽  
Rc Beams ◽  
Test Results ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Accuracy Test ◽  
New Models ◽  
Debonding Load

intermediate crack-induced debondingis one of the most dominant failure modes in FRP-strengthened RC beams. Different code models and provisions have been proposed to mitigateintermediate crack-induced debondingfailure.However, these models and provisions can not mitigate this failure mode effectively. Recnetly, new models have been proposed to solve this problem. Out of all the existing models, four typical ones are investigated in the current study. A comprehensivecomparison among these models is carried out in order to evaluate their performance and accuracy. Test results offlexural specimens with intermediate crack-induced debonding failurecollected from the existing literature are used in the current comparison. The effectivenessand accuracy of each model have been evaluated based on these experimental results. It is shown that the current modals are all conservative and inadequite to effectively mitigate intermediate crack-induced debonding in flexurally strengthened members.

Stabilization of Weak Clay with Strong Sand and Geogrid at Sand-Clay Interface

1998 ◽  
Vol 1611 (1) ◽  
pp. 55-62 ◽  
Author(s):  
Braja M. Das ◽  
Kim H. Khing ◽  
Eun C. Shin
Keyword(s):  
Bearing Capacity ◽  
Model Test ◽  
Soil Layer ◽  
Granular Soil ◽  
Laboratory Model ◽  
Test Results ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Base Course ◽  
Granular Base

The load-bearing capacity of a weak clay subgrade can be increased by placing a strong granular base course of limited thickness on top of the clay layer. The load-bearing capacity can be increased further, or the thickness of the granular base course can be reduced, by separating both layers by a geogrid. Laboratory model test results for the ultimate bearing capacity of a rigid strip loading on the surface of a granular soil underlain by a soft clay with a layer of geogrid at the interface of the two soils are presented. The optimum thickness of the granular soil layer and the critical width of the geogrid layer required to derive the maximum benefit from the reinforcement were determined. Model test results on the permanent settlement of the rigid strip load caused by cyclic loading of low frequency are presented.

Experimental Study on Load Bearing Capacity of Prefabricated Partially Encased Composite Beams

2021 ◽  
pp. 2150104
Author(s):  
Kai Wu ◽  
Shiqi Lin ◽  
Xiaoyi Liu ◽  
Fanshen Mao ◽  
Chengwei Tan
Keyword(s):  
Bearing Capacity ◽  
Superposition Principle ◽  
Great Influence ◽  
Reduction Rate ◽  
Test Results ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Shear Span ◽  
Bending Capacity ◽  
Negative Effect

To study the load bearing capacity of prefabricated partially encased composite (PEC) beams, 12 specimens were tested under cyclic loadings. According to the test results, when shear span ratio increases, the failure mode of the specimen changes from shear to bending, while the load bearing capacity of specimens decreases. Some specimens showed asymmetric damage of concrete on both sides of steel web, causing specimens’ bearing capacity to be controlled by bending and shearing as well as by torsion. The use of threaded rods has little effect on the ultimate load of prefabricated PEC beams, but has a great influence on the reduction rate of the load with the increase in shear span ratio. Using the superposition principle, a formula for calculating the shearing capacity of prefabricated PEC beams was proposed. Based on the plane section hypothesis, a method for predicting the bending capacity was also proposed. Two reduction factors were proposed to account for the negative effect of asymmetric damage on the bearing capacity and the weakened bending capacity of specimens without threaded rods. The calculated results match well with the experimental ones. Therefore, they can be used to predict the bending and shearing capacity of prefabricated PEC beams, while providing a reference for engineering design.

Evaluation of Main Code Models for Predicting Flexural Load-Bearing Capacity against Intermediate Crack-Induced Debonding in FRP-Strengthened RC Beams

2011 ◽  
Vol 71-78 ◽  
pp. 1465-1468
Author(s):  
Gui Bing Li ◽  
Yu Gang Guo ◽  
Xiao Yan Sun
Keyword(s):  
Bearing Capacity ◽  
Failure Modes ◽  
Experimental Results ◽  
Rc Beams ◽  
Test Results ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Accuracy Test ◽  
Comprehensive Comparison ◽  
Code Provisions

Intermediate crack-induced debonding is one of the most dominant failure modes in FRP-strengthened RC beams. Different code models and provisions have been proposed to predict intermediate crack-induced debonding failure. Out of all the existing code provisions and models, four typical ones are investigated in the current study. A comprehensive comparison among these code provisions and models is carried out in order to evaluate their performance and accuracy. Test results of flexural specimens with intermediate crack-induced debonding failure collected from the existing literature are used in the current comparison. The effectiveness and accuracy of each model have been evaluated based on these experimental results. It is shown that the current recommendations are inadequite to effectively mitigate intermediate crack-induced debonding in flexurally strengthened members.

Time-Dependent Load Bearing Capacity of Corroded R.C. Columns in Atmosphere Environment

2011 ◽  
Vol 50-51 ◽  
pp. 859-863
Author(s):  
Qiang Li ◽  
Nan Guo Jin ◽  
Xian Yu Jin
Keyword(s):  
Bearing Capacity ◽  
Time Dependent ◽  
Test Results ◽  
Equilibrium Equations ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Bond Behavior ◽  
Capacity Model ◽  
Model Predictions ◽  
Atmosphere Environment

As a supporting member of concrete structures, the reliability of the columns is of critical importance. To have models targeted to estimating the residual load-bearing capacity of corroded reinforced concrete (R.C.) columns so that inspection procedures and maintenance interventions can be well conducted, a time-dependent capacity model for corroded R.C. column is presented. The model was based on equilibrium equations on which load-bearing capacity of R.C. column at given time (year) can be predicted considering the overall deteriorations of rebar, concrete section, mechanical properties and bond behavior between corroded reinforcement and concrete. The model was verified by published literature test results of corroded R.C. columns served in atmosphere environment for years. The comparison of the model predictions with the test results shows the validity of the model. In the end, considerations for use of the model were suggested.

Simplified Model to Predict Load-Bearing Capacity of Concrete-Filled Steel Tubular Laced Column

2013 ◽  
Vol 405-408 ◽  
pp. 1041-1045 ◽  
Author(s):  
Lian Qiong Zheng ◽  
Shu Li Guo ◽  
Ji Zhong Zhou
Keyword(s):  
Bearing Capacity ◽  
Slenderness Ratio ◽  
Steel Tube ◽  
Simplified Model ◽  
Test Results ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Concrete Filled Steel Tube ◽  
Simplified Method ◽  
Equivalent Slenderness Ratio

A simplified method using an equivalent slenderness ratio was suggested to calculate load-bearing capacity of concrete-filled steel tubular laced column in this paper. The significant differences between compressive and tensile strengths of concrete-filled steel tube were considered. The comparisons between the predicted Nuc and the tested Nue showed that the predicted method gives generally good predictions of the test results.

Multidimensional load-bearing behaviour of timber-concrete composite road bridges with consideration of flexibility of connections

2021 ◽  
Author(s):  
Paul Dreifke ◽  
Tim Göckel ◽  
Andreas Laubach ◽  
Jürgen Schaffitzel‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌
Keyword(s):  
Bearing Capacity ◽  
Structural Design ◽  
Composite Structures ◽  
Vertical Direction ◽  
Structural Performance ◽  
Test Results ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Secondary Load ◽  
Composite Bridges

<p>Timber-concrete-composite structures for road bridges could be much more often used in the field of medium-span road bridges due to their good ecological and structural performance. Therefore, an appropriate consideration of the punctual connections usually used for such bridges is necessary. Those connectors have a large load-bearing capacity and stiffness. While there are established methods for determining the stiffness and load-bearing capacity in the main longitudinal load- bearing direction, the secondary load-bearing behaviour in transverse and vertical direction is usually not determined for those bridges. By assessing test results and evaluation of FE simulations, this article presents an approach of how a calculation method can be derived that makes the structural design of timber-concrete-composite bridges safely even in more demanding application scenarios.</p>

scholarly journals The Problem of Compressive Strength in Direction Perpendicular to the Grains on Example of Tests of the Load-Bearing Capacity of the Continuously Supported Timber-Frame Sill Plates

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1160
Author(s):  
Janusz Brol ◽  
Jan Kubica ◽  
Marek Węglorz
Keyword(s):  
Compressive Strength ◽  
Bearing Capacity ◽  
Current Approach ◽  
Full Scale ◽  
Test Results ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Timber Frame ◽  
Test Elements ◽  
Sill Plate

This paper presents a discussion of the problem of compressive strength in a direction perpendicular to the grains based on test results of the joints made by timber posts and sill plate. These tests accompanied a larger series of full-scale tests of timber frame walls. The test elements were made of solid softwood (spruce). The wood moisture was low, which corresponds to the real working conditions of these elements in the walls of a building (low humidity is typical for dry wood in the built-in wall of a real building). In the tests, the compression strength of timber perpendicular to the grain was exceeded in the sill plate in the area in contact with the posts. Shortly before reaching the state of failure, large displacements in the sill plate were measured on the contact surface with the post, and the grains in the sill plates were cut off at the edge of the post. The full-scale test results showed an overestimation of the load-bearing capacity in compression perpendicular to the grain when calculated on the basis of EN 1995-1-1+A1:2008 (Eurocode 5), and, therefore, the need to modify the current approach for determining it.

scholarly journals Nacre inspired 3D printing construction for high performance structural member

2019 ◽  
Vol 275 ◽  
pp. 02005
Author(s):  
Jiangtao Yu ◽  
Junhong Ye
Keyword(s):  
Bearing Capacity ◽  
High Performance ◽  
Image Correlation ◽  
Test Results ◽  
Load Bearing Capacity ◽  
Critical Crack ◽  
Load Bearing ◽  
Hierarchical Assembly ◽  
Four Point Bending ◽  
Flexural Ductility

Inspired by the nacre’s hierarchically assembled structure, the authors tried to use ultra-high ductile cementitious composites (UHDCC) and stack approach to fabricate structure possessing high flexural ductility and load bearing capacity. A series of beams with specially design was constructed, i.e., monolithically cast beams, monolithically stacked beams and hierarchically stacked beams. Four-point bending tests were carried out to explore the effect of hierarchical assembly on load bearing capacity, flexural deformation and flexural toughness. The test results have indicated that the monolithically stacked beams outperform the monolithically cast beams in both deformability and loading bearing capacity, indicating the effectiveness of stack-based construction. Moreover, the setup of connect/separation between layers further improves the flexural ductility of the hierarchically stacked beams, as compared with the monolithically stacked beams. Digital Image Correlation (DIC) observations indicate that the nacreous-like structure of the hierarchically stacked beam helps to trigger crack deflecting and branching between layers and inside matrix, lead to limited slide between layers, thus effectively relieving concentrated strain inside matrix, postponing the emergence of the critical crack and consequently improving the flexural ductility of nacreous-like UHDCC beams.

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