scholarly journals Uplift Test and Design Method for Bearing Capacity of Isolated Spread Concrete Foundation Slab with Large Width-to-Height Ratio

2018 ◽  
Vol 2018 ◽  
pp. 1-16
Author(s):  
Yuanqi Li ◽  
Xiaoliang Qin ◽  
Jinhui Luo ◽  
Meng Xiao ◽  
Cong Hua
Keyword(s):  
Bearing Capacity ◽  
Design Method ◽  
Numerical Models ◽  
Correction Coefficient ◽  
Uplift Capacity ◽  
Height Ratio ◽  
Foundation Slab ◽  
Concrete Foundation ◽  
Practical Engineering ◽  
Large Width

This paper is focused on the experimental study and numerical simulation of isolated spread concrete foundation slab with a large width-to-height ratio (in short ISCFS-LWR) to investigate the failure modes and uplift bearing capacity, as well as the design method of uplift capacity. First, a total of 16 isolated spread concrete foundation slabs with the width-to-height ratio varied from 1.5 to 4 and the hypotenuse slope varied from 10° to 30° were tested under uplift load. Based on the test results, effects of the width-to-height ratio and the hypotenuse slope on uplift bearing capacity of ISCFS-LWR were analyzed and discussed. Then, several numerical models were built using the finite element software ABAQUS and the results of numerical analysis agreed well with the test results. Furthermore, the cross-sectional performance of ISCFS-LWR was studied, and the coefficients of internal force arm were also evaluated further using previous validated numerical models. To obtain the suggested design method of uplift capacity for the foundation slab, effective width correction coefficient k and slope correction coefficient j were introduced to propose a design formula. Finally, the proposed design method was applied to a practical engineering, and the economic indicators obtained from the suggested design method were compared with that from the original design method. The results of this paper showed that the correction coefficient jsks based on numerical analysis agreed well with the recommended correction coefficient jk, and the error was between 1% and 3.4%, by which the reasonability of the proposed design method of uplift capacity for ISCFS-LWR has been proved. It can also be found that the economic benefits of the practical engineering in this paper were obvious due to the suggested design method, and this paper can provide a reference for other engineering practices and the further research work on ISCFS-LWR.

Longitudinal Shear Analysis of Composite Slabs with Prepressed Embossments

2015 ◽  
Vol 1122 ◽  
pp. 265-268
Author(s):  
Josef Holomek ◽  
Miroslav Bajer ◽  
Martin Vild
Keyword(s):  
Bearing Capacity ◽  
Design Method ◽  
Numerical Models ◽  
Longitudinal Shear ◽  
Small Scale ◽  
Shear Tests ◽  
Bending Tests ◽  
Load Bearing ◽  
Composite Slabs ◽  
Shear Bearing Capacity

Composite slabs with prepressed embossments present an effective solution for horizontal load bearing structures. Sheeting serves as a formwork in construction stage and as a tension bearing member after hardening of concrete. There is no need for additional tensile reinforcement in case of sufficient longitudinal shear bearing capacity of the embossments. Longitudinal shear bearing capacity is not precisely determined when designing according to nowadays standards. Full scale bending tests of the slabs are used to determine characteristics for m – k method or partial connection method. Bending tests are expensive and space demanding. Alternatively small-scale shear tests can be used to determine shear characteristics of the sheeting. However, shear tests cannot include all the effects affecting the bearing capacity of bended slab, such as effect of curvature or distribution of load. Therefore, related design method has to be used to determine load bearing capacity of the slab in bending. This paper extends achievements presented by the authors in contribution in CRRB 2013. The results of small-scale tests are compared with results of numerical models of the slab in shear. Numerical models are created in two different finite element codes. Setting of steel-concrete interface properties in the models is validated using data from literature.

Design and Research of Double-Drum Winch with Anti-Pressure Wheel

2012 ◽  
Vol 479-481 ◽  
pp. 1709-1713
Author(s):  
Kai An Yu ◽  
Tao Yang ◽  
Chang Zhi Gong
Keyword(s):  
Finite Element ◽  
Bearing Capacity ◽  
Finite Element Methods ◽  
Design Method ◽  
New Method

In view of the problems of large stress and severe bearing heating in double-drum winch at present, this paper adopted a new method to enhance bearing capacity for double-drum winch by adding anti-pressure wheels between two drums. Finite element methods were used to analyze the strength of 4000kN-traction double-drum winches with anti-pressure wheels and without anti-pressure wheels respectively. The results of the analysis revealed that the stress of the cylinder bearing decreased from 264MPa to 167MPa. The new method by adding anti-pressure wheels had remarkably improved the endurance of the bearing. Therefore, the design method can be widely used in large-traction double-drum winch.

scholarly journals Application of Artificial Neural Networks for Predicting the Bearing Capacity of Shallow Foundations on Rock Masses

2021 ◽  
Author(s):  
M. A. Millán ◽  
R. Galindo ◽  
A. Alencar
Keyword(s):  
Bearing Capacity ◽  
Analytical Solutions ◽  
Shear Failure ◽  
Numerical Models ◽  
Computational Effort ◽  
Shallow Foundations ◽  
Geological Strength Index ◽  
Rock Masses ◽  
Ann Model ◽  
Artificial Neural

AbstractCalculation of the bearing capacity of shallow foundations on rock masses is usually addressed either using empirical equations, analytical solutions, or numerical models. While the empirical laws are limited to the particular conditions and local geology of the data and the application of analytical solutions is complex and limited by its simplified assumptions, numerical models offer a reliable solution for the task but require more computational effort. This research presents an artificial neural network (ANN) solution to predict the bearing capacity due to general shear failure more simply and straightforwardly, obtained from FLAC numerical calculations based on the Hoek and Brown criterion, reproducing more realistic configurations than those offered by empirical or analytical solutions. The inputs included in the proposed ANN are rock type, uniaxial compressive strength, geological strength index, foundation width, dilatancy, bidimensional or axisymmetric problem, the roughness of the foundation-rock contact, and consideration or not of the self-weight of the rock mass. The predictions from the ANN model are in very good agreement with the numerical results, proving that it can be successfully employed to provide a very accurate assessment of the bearing capacity in a simpler and more accessible way than the existing methods.

scholarly journals Optimal Unimodular Sequences Design Method for Active Sensing Systems

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Ze Li ◽  
Ping Li ◽  
Xinhong Hao ◽  
Xiaopeng Yan
Keyword(s):  
Optimization Problems ◽  
Design Method ◽  
Correlation Coefficients ◽  
Continuous Phase ◽  
Active Sensing ◽  
Sidelobe Level ◽  
One Dimensional ◽  
Sensing Systems ◽  
Practical Engineering ◽  
Dimensional Optimization

In active sensing systems, unimodular sequences with low autocorrelation sidelobes are widely adopted as modulation sequences to improve the distance resolution and antijamming performance. In this paper, in order to meet the requirements of specific practical engineering applications such as suppressing certain correlation coefficients and finite phase, we propose a new algorithm to design both continuous phase and finite phase unimodular sequences with a low periodic weighted integrated sidelobe level (WISL). With the help of the transformation matrix, such an algorithm decomposes the N-dimensional optimization problem into N one-dimensional optimization problems and then uses the iterative method to search the optimal solutions of the N one-dimensional optimization problems directly. Numerical experiments demonstrate the effectiveness and the convergence property of the proposed algorithm.

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.

Prediction of Ultimate Bearing Capacity of Half-Screwed Pile by Integrated Exponential Function Model

2013 ◽  
Vol 353-356 ◽  
pp. 881-885
Author(s):  
Jian Xiong Liu ◽  
Yan Yan Gao ◽  
Xiu Hua Li
Keyword(s):  
Bearing Capacity ◽  
Functional Model ◽  
Ultimate Bearing Capacity ◽  
Model Solution ◽  
Least Square ◽  
Single Pile ◽  
Engineering Research ◽  
Exponential Functional ◽  
Practical Engineering ◽  
Difference Form

This study fitted the measured loading-settlement curve of half-screwed pilewith least square model solution of difference form of integrated exponential functional model, and predict ultimate bearing capacity of half-screwed pile according to the fitted curve of maximum curvature point. Combined with practical engineering research, the study explored the feasibility, rationality and limitations of predicting the half-screwed single pile ultimate bearing capacity with least square model solution of difference form of integrated exponential functional model, and provided the theoretical basis for the popularization and application of the half-screwed pile.

scholarly journals Calculation of Ultimate Bearing Capacity of Pile Foundations of Highway Bridges under the Coupling of Steep Slope and Karst

2020 ◽  
Vol 198 ◽  
pp. 02017
Author(s):  
Zhongju Feng ◽  
Shaofen Bai ◽  
Wu Min ◽  
Jingbin He ◽  
Zhouyi Huang ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Pile Foundation ◽  
Highway Bridges ◽  
Ultimate Bearing Capacity ◽  
Steep Slope ◽  
Karst Area ◽  
Correction Coefficient ◽  
Finite Element Software ◽  
Calculation Results ◽  
Vertical Bearing

In order to study the influence of steep slope-karst coupling on the vertical bearing characteristics of pile foundation, the orthogonal simulation tests of pile foundation under 4 different roof thickness and 5 different slope are carried out by using Marc finite element software, and the correction coefficient of vertical partial bearing capacity of pile foundation according to roof thickness and slope is put forward. The test results show that when the thickness of the roof is more than 3 times the pile diameter, the ultimate bearing capacity of the pile foundation tends to be stable, and the value is about 19% when the slope is 45°; the ultimate bearing capacity of the pile foundation decreases gradually with the increase of the slope, and the reduction reaches 29.83% when the slope is greater than 45°. According to the calculation results, the variation law of vertical partial bearing capacity of pile foundation is analyzed, and the calculation formula of standard value of vertical ultimate bearing capacity of pile foundation in steep slope karst area considering both roof thickness and slope is put forward, and the correction coefficients αi and β are put forward.

scholarly journals Analysis of Exploitation Damages of the Frame Scaffolding

2019 ◽  
Vol 284 ◽  
pp. 08008 ◽  
Author(s):  
Aleksander Robak ◽  
Michał Pieńko ◽  
Ewa Błazik-Borowa ◽  
Jarosław Bęc ◽  
Iwona Szer
Keyword(s):  
Bearing Capacity ◽  
Power Plants ◽  
Selection Process ◽  
Numerical Models ◽  
Technical Condition ◽  
Construction Sites ◽  
Size Type ◽  
Investment Size ◽  
Imminent Threat ◽  
Investment Location

The analyzes and classifications presented in the article were based on the research carried out in the years 2016 to 2018 on a group of over one hundred scaffoldings assembled and used on construction sites in different parts of Poland. During scaffolding selection process efforts were made to maintain diversification in terms of parameters such as scaffolding size, investment size, type of investment, location and nature of conducted 5works. This resulted in the research being carried out on scaffoldings used for church renovation in a small town or attached to the facades of classic apartment blocks, as well as on scaffoldings used during construction of skyscrapers or facilities of the largest power plants. This variety allows to formulate general conclusions about the technical condition of used frame scaffoldings. Exploitation damages of the frame scaffolding elements were divided into three groups. The first group includes damages to the main structural components, which reduce the strength of the scaffolding elements and hence the whole structure. The qualitative analysis of these damages was made based on numerical models that take into account the geometry of the damage and based on computational nonlinear static analyzes. The second group focuses on exploitation damages such as the lack of a pin on the guardrail bolt which may cause an imminent threat to people using scaffolding. These are local damages that do not affect the bearing capacity and stability of the whole structure but are very important for safe use. The last group consider damages that reduce only aesthetic values and do not have direct impact on bearing capacity and safety of use. Apart from qualitative analyzes the article will present quantitative analyzes showing how frequently given type of damage occurs.

scholarly journals Church enclosure walls bearing capacity estimations and its validation on 3D models

2020 ◽  
Vol 310 ◽  
pp. 00023
Author(s):  
Pavel Kuklik ◽  
Martin Valek ◽  
Ivana Bozulic ◽  
Pratik Gajjar ◽  
Chandrashekhar Mahato ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Numerical Models ◽  
3D Models ◽  
Present Calculation ◽  
Fem Modeling ◽  
Structural Element ◽  
Historical Structures ◽  
Numerical Tools ◽  
Tools And Techniques

The paper deals with the nonlinear computational modeling of the baroque enclosure masonry walls. The main tasks are input parameters for efficient advanced numerical tools and techniques, which are based on nonlinear and quasi brittle constitutive FEM modeling. For the work was used the knowledge and results from the Broumov Group Churches survey acquired in the frame of international SAHC university cooperation. The goal of the contribution are real bearing capacity parameters of the composite enclosure walls, which leads from standard homogenization techniques. With regards to the material micro modeling of different wall configuration in longitudinal and transversal direction was done with ATENA 2D software to evaluate the safe bearing capacity of the walls. The set of models aim to assess the bearing capacity of the enclosure wall, which is the main structural element in the church. In detail, we will present results from the numerical investigation, and partial in situ testing, from Vižňov, Ruprechtice and Otovice. Finally, we will present calculation of cracks propagation on full 3D church models. Concerning historical structures, it is one way how to validate the quality of estimations and validate numerical models.

scholarly journals Bearing Capacity Analysis and Zoning of Kathmandu for Shallow Foundations

2018 ◽  
Vol 4 ◽  
pp. 111-117
Author(s):  
Ram Krishna Danai ◽  
Indra Prasad Acharya
Keyword(s):  
Bearing Capacity ◽  
Numerical Models ◽  
Failure Criteria ◽  
Unit Weight ◽  
Soil Parameters ◽  
Primary Concern ◽  
Borehole Data ◽  
Element Analysis ◽  
Theoretical Approaches ◽  
Coulomb Failure

The bearing capacity of foundation is the primary concern in the field of geotechnical engineering. In this study numerical models are developed for each of the secondary borehole data collected around Kathmandu valley. Finite element analysis (i.e. PLAXIS 2D) is carried out using Mohr-coulomb failure criteria to represent two dimensional soil models. Foundation is aimed to model as square footing and prescribed settlement of 10% of footing width is provided to obtain corresponding bearing capacity. In plaxis, effective stress is considered as an ultimate bearing capacity. Drained behavior with axisymmetical models have been considered for soil model in plaxis software. Various soil parameters like C (Cohesion), γ (unit weight), Φ (Frictional angle), ν (Poison ratio), E (Elasticity) for each 1.5m and 3m depths have been considered in models and in theoretical approaches.

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