Numerical Tests on Laterally Loaded Drilled Shafts Socketed in Rock

2014 ◽  
Vol 919-921 ◽  
pp. 706-709
Author(s):  
Shuai Jie Yuan ◽  
Kun Yong Zhang ◽  
Zi Jian Liu ◽  
Jian Cheng Li
Keyword(s):  
Rock Mass ◽  
Bearing Capacity ◽  
Field Tests ◽  
Accurate Method ◽  
Ultimate Bearing Capacity ◽  
Drilled Shafts ◽  
Displacement Curve ◽  
Numerical Tests ◽  
Load Displacement ◽  
Laterally Loaded

Ultimate lateral bearing capacity of rock mass is the base of the research of laterally loaded drilled shafts socketed in rock mass. The ultimate bearing capacity is often not available because of the limitation of loading ability in field tests. Numerical tests are used here to simulate the drilled shafts socketed in rock mass and expand the load-displacement curve obtained from field tests. Common methods of determining ultimate lateral bearing capacity are also analyzed and compared here. At last, a relatively accurate method of determining laterally loaded drilled shafts socketed in rock mass is recommended.

scholarly journals Analysis on the Mechanical Performance of the Joints of the Wheel-coupler type formwork Support

2021 ◽  
Vol 261 ◽  
pp. 02070
Author(s):  
Shilong Jia ◽  
Fang Zhou ◽  
Zhongliang Chen
Keyword(s):  
Mechanical Properties ◽  
Bearing Capacity ◽  
Mechanical Performance ◽  
Ultimate Bearing Capacity ◽  
Displacement Curve ◽  
Ansys Software ◽  
Rotational Stiffness ◽  
Non Linear ◽  
Tension And Compression ◽  
Load Displacement

In order to study the mechanical properties of the joints, ANSYS software was used to simulate and analyse the failure form, ultimate bearing capacity, load-displacement curve and the rotational stiffness of the wheel-coupler joint node under force. Results: The wheel-coupler joint node has obvious non-linear characteristics when subjected to force; The bilateral symmetric tension and compression state could better reflect the failure form and deformation of the joint; The rotational stiffness of the wheel-coupler joint node under tension and bending was greater than that under bending and torsion, and was greater than that under tension, bending and torsion.

scholarly journals Influence of Natural Cavities on the Design of Shallow Foundations

2020 ◽  
Vol 10 (3) ◽  
pp. 1119
Author(s):  
Jesús Luis Benito Olmeda ◽  
Javier Moreno Robles ◽  
Eugenio Sanz Pérez ◽  
Claudio Olalla Marañón
Keyword(s):  
Rock Mass ◽  
Bearing Capacity ◽  
Ultimate Bearing Capacity ◽  
Shallow Foundation ◽  
Rock Masses ◽  
Volcanic Origin ◽  
Rock Types ◽  
Geometric Configurations ◽  
Relative Eccentricity ◽  
Decisive Parameter

When inner cavities of significant dimensions exist in natural rocks, problems arise when a shallow foundation for a building, bridge or other structure is builtonthem. Thus, taking one of the most representative cavity geometries in nature, the ellipsoidal horizontal shape, the main objective of this study is to obtain the ultimate bearing capacity of the foundation with cavities of different sizes and positions, on rock masses with different strengths and deformation characteristics. The study focuses on natural rocks of karst origin (in limestones, dolomites or gypsums) and of volcanic origin. The ultimate bearing capacity is determined relative to a situation without the existence of the cavity for different cavern positions and sizes, rock types (mi), strengths (UCS), and states (GSI) of the rock mass. The results showed that the most decisive parameter is the relative eccentricity. The influence of the rock type (Hoek’s parameter mi) is, for practical purposes, negligible (lower than 10%). The strength and condition of the rock mass (parameters UCS and GSI) have relatively little influence on the results obtained. This study aims to provide a simple design criteria for universal use, with different geometric configurations and qualities of rock masses that can be used directly without the need for sophisticated calculations by the designer.

scholarly journals Axial Compression Performance of Square Thin Walled Concrete-Filled Steel Tube Stub Columns with Reinforcement Stiffener under Constant High-Temperature

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1098 ◽  
Author(s):  
Xuetao Lyu ◽  
Yang Xu ◽  
Qian Xu ◽  
Yang Yu
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Bearing Capacity ◽  
Numerical Models ◽  
Steel Tube ◽  
Ultimate Bearing Capacity ◽  
Displacement Curve ◽  
Concrete Filled Steel Tube ◽  
Finite Element Software ◽  
Thin Walled

This study investigated the axial compressive performance of six thin-walled concrete-filled steel tube (CFST) square column specimens with steel bar stiffeners and two non-stiffened specimens at constant temperatures of 20 °C, 100 °C, 200 °C, 400 °C, 600 °C and 800 °C. The mechanical properties of the specimens at different temperatures were analyzed in terms of the ultimate bearing capacity, failure mode, and load–displacement curve. The experiment results show that at high temperature, even though the mechanical properties of the specimens declined, leading to a decrease of the ultimate bearing capacity, the ductility and deformation capacity of the specimens improved inversely. Based on finite element software ABAQUS, numerical models were developed to calculate both temperature and mechanical fields, the results of which were in good agreement with experimental results. Then, the stress mechanism of eight specimens was analyzed using established numerical models. The analysis results show that with the increase of temperature, the longitudinal stress gradient of the concrete in the specimen column increases while the stress value decreases. The lateral restraint of the stiffeners is capable of restraining the steel outer buckling and enhancing the restraint effect on the concrete.

Experimental Study on Circular Hybrid SCCC Columns under Axial Compressive Load

2011 ◽  
Vol 368-373 ◽  
pp. 369-372
Author(s):  
Zhu Yan Li ◽  
Yong Jun Liu ◽  
Dong Wang
Keyword(s):  
Bearing Capacity ◽  
Test Specimen ◽  
Compressive Load ◽  
Strain Curve ◽  
Steel Tube ◽  
Ultimate Bearing Capacity ◽  
Displacement Curve ◽  
Compressive Performance ◽  
Core Concrete

The tests are order to investigate the axial compressive performance of the new circular hybrid Steel-Concrete- CFRP-Concrete column (simply called SCCC column).SCCC column is composed of steel tube, annular concrete, CFRP tube and core concrete. Axial ultimate bearing capacity test was performed on 3 SCCC columns, from which we gains the law of affecting SCCC columns, the load-strain curve and load-displacement curve of SCCC columns, and compare the test results of the test specimen with different annular concrete thicknesses, from which we finds that after the relationship curve of test specimen with small annular concrete thickness reaches yield load, the bearing capacity starts to decline, and then continues to rise till the ultimate load is reached and the test specimen is damaged. The result shows that the smaller the annular concrete thickness is, the greater the axial ultimate bearing capacity of SCCC column is, and also indicates that CFRP tube plays a role of binding and constraining to the core concrete in later period of loading the test specimens.

Experimental and large-scale field tests of grid-anchor system performance in increasing the ultimate bearing capacity of granular soils

2016 ◽  
Vol 53 (7) ◽  
pp. 1047-1058 ◽  
Author(s):  
M. Mosallanezhad ◽  
N. Hataf ◽  
S.H. Sadat Taghavi
Keyword(s):  
Bearing Capacity ◽  
Large Scale ◽  
Field Tests ◽  
Experimental Tests ◽  
Ultimate Bearing Capacity ◽  
Soil Reinforcement ◽  
Granular Soils ◽  
Anchor System ◽  
Scale Field ◽  
Large Scale Field

Soil reinforcement by means of geogrid is an effective method of increasing the ultimate bearing capacity (UBC) of granular soils. In this study a new system, created by adding cubic anchors to ordinary geogrids, is introduced to increase the UBC of granular soils. This system is called “grid-anchor” (G-A). To analyse the performance of the G-A system in increasing the UBC of granular soils, 45 experimental tests and 9 field tests were performed, the results of which show that the G-A system is 1.8 times more capable than ordinary geogrids in increasing the UBC in square foundations. Furthermore, the failure of soil reinforced by the ordinary geogrid takes place at a settlement of 9% of the foundation width, while the same value for the G-A system is almost 13%.

scholarly journals Local Thickening and Friction Reducing to Constant Resistance in a Prefolded Energy Absorption Device

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Hailiang Xu ◽  
Jiaqi Song ◽  
Dong An ◽  
Yimin Song ◽  
Xiangfeng Lv
Keyword(s):  
Friction Coefficient ◽  
Plastic Strain ◽  
Bearing Capacity ◽  
Energy Absorption ◽  
Concave Side ◽  
Original Structure ◽  
Displacement Curve ◽  
Obvious Effect ◽  
Constant Resistance ◽  
Load Displacement

The energy absorption support for impact resistance used in mining engineering is a prefolded energy absorption device. In this paper, through the quasistatic compression test and numerical simulation, the relationship between the deformation process, load-displacement curve, and plastic strain of the original prefolded energy absorbing device is studied. It is found that the concave side stiffness has an obvious effect on the first and second descending sections of the load-displacement curve, and the friction coefficient has an obvious effect on the second ascending section of that. In order to make the prefolded energy absorption device reach the state of constant resistance where the reaction load does not fluctuate or the fluctuation is small in the crushing process, the plastic strain is restrained by thickening the local area of the concave side, which effectively reduces the descending amplitude of the load-displacement curve. Whether continuoues deformation occurs is affected by the friction coefficient. Finally, a constant resistance energy absorption device is designed by thickening the concave side and reducing the friction coefficient. Compared with the original structure, the maximum bearing capacity of the constant resistance energy absorption device is basically unchanged, the average bearing capacity is increased by 29%, the total energy absorption is increased by 111%, the specific energy absorption is increased by 119%, and the load-displacement curve variance is reduced to 3% of the original structure.

Three-Dimensional Finite Element Analysis on the Bearing Capacity of Bucket Foundation with Different Ratios of Diameter to Height

2014 ◽  
Vol 488-489 ◽  
pp. 689-695
Author(s):  
Shuai Liu ◽  
Wen Bai Liu ◽  
Liang Yang
Keyword(s):  
Bearing Capacity ◽  
Three Dimensional ◽  
Vertical Displacement ◽  
Ultimate Bearing Capacity ◽  
Displacement Curve ◽  
Maximum Displacement ◽  
Element Analysis ◽  
Bucket Foundation ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

The ABAQUS software is used for simulating the vertical bearing capacity of bucket foundation of different ratios of diameter to height and the analysis for the stress and displacement distribution and load-displacement curve. When the bucket foundation is under pressure, the vertical stress of the soil distribution changes from the bottom to the top, and then spreads to most part of the soil in the bucket foundation. The vertical displacement of the soil develops from the top of foundation and spreads inside, then expands to the outside range, the maximum displacement occurs both at the bottom and inside. According to the analysis of the ultimate bearing capacity of the bucket foundation, it could be found that when the height of the bucket foundation remains unchanged, the ultimate bearing capacity increases with the increasing ratio of diameter to height. If the ratio of diameter to height is less than 1.2, the ultimate strength increases significantly. If the ratio of diameter to height is greater than 1.2, the increasing speed of the ultimate bearing capacity changes slowly. When the diameter of the bucket foundation is constant, the ultimate bearing capacity decreases as the ratio of diameter to height gradually increases, and it decreases at a homogeneous speed. So the ratio of diameter to height 1.2 can be used as the optimum point of the ratio of diameter to height of the bucket foundation.

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