REASONING ON IMPLEMENTATION OF FROST PROTECTED SHALLOW FOUNDATIONS

2016 ◽  
Vol 3 (1) ◽  
Author(s):  
Lilita Ozola ◽  
Guntis Andersons
Keyword(s):  
Data Processing ◽  
Design Method ◽  
Temperature Data ◽  
Shallow Foundations ◽  
Shallow Foundation ◽  
Silty Sand ◽  
Design Parameters ◽  
Climatic Data ◽  
Foundation Design ◽  
The Baltic

Implementation of frost protected shallow foundations (with insulation) in frost susceptible soils in the areas of the Baltic region is an item under discussion. A design method recommended by EN ISO 13793 has been applied. The design base is the EN 1997-1 which includes conditions and valid climatic data for the localities in the Republic of Latvia. The study contains the results of external air temperature data processing from the last 70 years, and consequently a determination of a freezing index value, and moreover pointing out the variation depending on the reference period taken. Results of temperature data processing for decades of winter seasons testify that quite distinctive frost protection levels may be defined for shallow foundation design parameters depending on the number of frost seasons sampled. The specific design results were obtained for eccentrically loaded columnar spread foundations of an unheated building insulated to reduce heat loss from the soil below the foundations keeping the subgrade soil unfrozen. As a result of the research the conclusion about the benefits expected has been presented, based on the comparison of concrete consumption and soil excavation volumes from different localities in Latvia. It has been concluded that the cost effectiveness of heated foundations correlates closely with the type of frost-heaving soil. Use of frost protected shallow foundations in clayey soils leads to an increase of ground volume to be excavated and filled back, and concrete consumption for foundations decreases. In silty sand soils, if the required foundation depth is less than some definite level, both reductions may be achieved by shifting the ground, and in concrete consumption as well.

Research on the Optimization Design of the Bridge Foundation Bored Piles

2014 ◽  
Vol 1030-1032 ◽  
pp. 851-854
Author(s):  
Yong Chun Cheng ◽  
Ji Zhong Zhao ◽  
Peng Zhang ◽  
Jing Lin Tao ◽  
Ya Feng Gong
Keyword(s):  
Optimization Design ◽  
Design Method ◽  
Design Parameters ◽  
Foundation Design ◽  
Pile Diameter ◽  
Bored Piles ◽  
Vertical Bearing ◽  
Bridge Foundation ◽  
Vertical Bearing Capacity ◽  
Pile Length

This paper improves the method of calculating the vertical bearing capacity of bored piles, and unifies calculation method of singe pile under horizontal force, as well adds and modifies the design parameters of the specification, finally utilizes actual example to make a unified test of the above methods. The results proved that, through the optimization of bridge foundation design method of bored piles, it can significantly reduce construction cost, and makes the pile length, pile diameter, and reinforcement more safe and reasonable. At the same time, it has great directive significance to the design and construction of the bridge.

scholarly journals Criteria for Preliminary Design of an Arched Steel Bridge on Shallow Foundation Under Soil Liquefaction Conditions

2017 ◽  
Vol 11 (1) ◽  
pp. 1170-1190 ◽  
Author(s):  
Isabella Vassilopoulou ◽  
Vasiliki Kaymenaki ◽  
Charis J. Gantes ◽  
George Bouckovalas
Keyword(s):  
Seismic Isolation ◽  
Design Method ◽  
Soil Layer ◽  
Soil Liquefaction ◽  
Shallow Foundation ◽  
Preliminary Design ◽  
Steel Bridge ◽  
Foundation Design ◽  
Deep Foundation ◽  
Liquefiable Soil

Introduction: The research is based on a proposed new foundation design method of bridges on liquefiable soil, consisting of using a shallow foundation and exploiting the liquefiable soil layer as natural seismic isolation, replacing thus the commonly employed deep foundation method. The use of this concept may be hindered by detrimental effects, such as large displacements and rotations that are expected to take place at the foundation of the structure during a strong seismic event, associated with permanent displacements due to the liquefaction phenomenon. Methods: The aim of the current study is to investigate the response of an arched steel bridge with two simply supported spans to displacements and rotations induced by soil liquefaction, delineate the acceptable limits of such ground movements that the bridge can sustain, avoiding the collapse of the superstructure, and define criteria for the preliminary design of the spread footing of the middle pier. To that effect, nonlinear analyses are performed, taking into account geometric and material nonlinearities. Displacements and rotations are imposed at the base of the pier and their amplitude is gradually increased until the first group of structural elements that reach failure is detected. Results and Conclusion: The values of displacements and rotations, for which failure occurs, specify the tolerable design limits. This is a first step towards investigating the feasibility of the above concept for bridges of this type.

scholarly journals Structural optimisation of shallow foundations for overhead power line

2020 ◽  
Vol 10 (2) ◽  
pp. 242-249
Author(s):  
Marsel A. Magomedov ◽  
Keyword(s):  
Finite Element ◽  
Structural Reliability ◽  
Power Line ◽  
Shallow Foundations ◽  
Shallow Foundation ◽  
Soil Conditions ◽  
Foundation Design ◽  
Geological Conditions ◽  
Complex Engineering ◽  
Overhead Power Line

The present work is aimed at studying the design of shallow foundations for overhead power line the towers under complex engineering and geological conditions. The study investigates existing designs and reveals their main shortcomings. In order to increase structural stability in complex soil conditions, the experience of constructing overhead power line towers using a shallow foundation is considered. The proposed shallow foundation option demonstrates increased strength and structural reliability. The shallow foundation design was carried out using the SCAD design software analysing the finite element model of static and dynamic loaded computation schemes, monitoring the structures for stability, checking metal systems for reliability and selecting disadvantageous combinations of forcing. The finite element method on which the software is based uses the movements and rotations of the structural nodes in the computation scheme as the main unknown variables. Two shallow foundation options are considered under equally complex soil conditions with the same loads, but a different arrangement of collar beams. Under complex engineering and geological conditions and the action of maximum loads, the calculation showed the greatest difference in the foundation settlement between the two options to increase by 2 times. The significance of the difficulties involved in increasing security of supply established by the development strategies of the electric power industry in Russia is presented. A design models for towers having shallow foundations, operated as beams of complex geometry, was selected. Experimental and analytical studies demonstrated the practical effectiveness of using the identified shallow foundation approach.

scholarly journals A modular design method based on TRIZ and AD and its application to cutter changing robot

2021 ◽  
Vol 13 (7) ◽  
pp. 168781402110343
Author(s):  
Mei Yang ◽  
Yimin Xia ◽  
Lianhui Jia ◽  
Dujuan Wang ◽  
Zhiyong Ji
Keyword(s):  
Modular Design ◽  
Design Method ◽  
Idea Generation ◽  
Design Parameters ◽  
Problem Analysis ◽  
Concept Design ◽  
Functional Requirements ◽  
Shield Tunneling ◽  
Structural Hierarchy ◽  
And Performance

Modular design, Axiomatic design (AD) and Theory of inventive problem solving (TRIZ) have been increasingly popularized in concept design of modern mechanical product. Each method has their own advantages and drawbacks. The benefit of modular design is reducing the product design period, and AD has the capability of problem analysis, while TRIZ’s expertise is innovative idea generation. According to the complementarity of these three approaches, an innovative and systematic methodology is proposed to design big complex mechanical system. Firstly, the module partition is executed based on scenario decomposition. Then, the behavior attributes of modules are listed to find the design contradiction, including motion form, spatial constraints, and performance requirements. TRIZ tools are employed to deal with the contradictions between behavior attributes. The decomposition and mapping of functional requirements and design parameters are carried out to construct the structural hierarchy of each module. Then, modules are integrated considering the connections between each other. Finally, the operation steps in application scenario are designed in temporal and spatial dimensions. Design of cutter changing robot for shield tunneling machine is taken as an example to validate the feasibility and effectiveness of the proposed method.

scholarly journals A Two-Round Optimization Design Method for Aerostatic Spindles Considering the Fluid–Structure Interaction Effect

2021 ◽  
Vol 11 (7) ◽  
pp. 3017
Author(s):  
Qiang Gao ◽  
Siyu Gao ◽  
Lihua Lu ◽  
Min Zhu ◽  
Feihu Zhang
Keyword(s):  
Optimal Design ◽  
Optimization Design ◽  
Design Method ◽  
Fluid Structure Interaction ◽  
Design Procedure ◽  
Design Parameters ◽  
Geometrical Parameters ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Aerostatic Spindle

The fluid–structure interaction (FSI) effect has a significant impact on the static and dynamic performance of aerostatic spindles, which should be fully considered when developing a new product. To enhance the overall performance of aerostatic spindles, a two-round optimization design method for aerostatic spindles considering the FSI effect is proposed in this article. An aerostatic spindle is optimized to elaborate the design procedure of the proposed method. In the first-round design, the geometrical parameters of the aerostatic bearing were optimized to improve its stiffness. Then, the key structural dimension of the aerostatic spindle is optimized in the second-round design to improve the natural frequency of the spindle. Finally, optimal design parameters are acquired and experimentally verified. This research guides the optimal design of aerostatic spindles considering the FSI effect.

Research on the Optimal Design Method of the Main Components for the Wheelchair Pickup

2013 ◽  
Vol 791-793 ◽  
pp. 799-802
Author(s):  
Ya Ping Wang ◽  
H.R. Shi ◽  
L. Gao ◽  
Z. Wang ◽  
X.Y. Jia ◽  
...  
Keyword(s):  
Parametric Design ◽  
Design Method ◽  
Basic Function ◽  
Design Parameters ◽  
Algorithm Optimization ◽  
Optimization Analysis ◽  
Research Designs ◽  
Optimal Design Method ◽  
Main Components

With the increasing of the aging of population all over the world, and With the inconvenience coming from diseases and damage, there will be more and more people using the wheelchair as a tool for transport. When it cant be short of the wheelchair in the daily life, the addition of the function will bring the elevation of the quality of life for the unfortunate. Staring with this purpose, the research designs a pickup with planetary bevel gear for the wheelchair. After determining the basic function of the wheelchair aids, the study determines the design parameters by using the knowledge of parametric design and completes the model for the system with Pro/E, on the other hand, it completes key components optimization analysis which is based on genetic algorithm optimization.

Development of High-Speed Response Electromagnetic Linear Actuator Using for Pneumatic Control Valve

2014 ◽  
Vol 532 ◽  
pp. 41-45 ◽  
Author(s):  
Myung Jin Chung
Keyword(s):  
Optimal Design ◽  
Dynamic Characteristics ◽  
High Speed ◽  
Design Method ◽  
Control Valve ◽  
Design Parameters ◽  
Linear Actuator ◽  
Analytic Model ◽  
Electromagnetic Linear Actuator ◽  
Quadratic Programming Method

Analytic model of electromagnetic linear actuator in the function of electric and geometric parameters is proposed and the effects of the design parameters on the dynamic characteristics are analyzed. To improve the dynamic characteristics, optimal design is conducted by applying sequential quadratic programming method to the analytic model. This optimal design method aims to minimize the response time and maximize force efficiency. By this procedure, electromagnetic linear actuator having high-speed characteristics is developed.

The Biomimetic Shark Skin Optimization Design Method for Improving Lubrication Effect of Engineering Surface

2014 ◽  
Vol 136 (3) ◽  
Author(s):  
Yan Lu ◽  
Meng Hua ◽  
Zuomin Liu
Keyword(s):  
Coefficient Of Friction ◽  
Optimization Design ◽  
Design Method ◽  
Theory Model ◽  
Tribological Performance ◽  
Design Parameters ◽  
Width Ratio ◽  
Textured Surface ◽  
Shark Skin ◽  
Biomimetic Surface

Nature has long been an important source of inspiration for mankind to develop artificial ways to mimic the remarkable properties of biological systems. In this work, a new method was explored to fabricate a biomimetic engineering surface comprising both the shark-skin, the shark body denticle, and rib morphology. It can help reduce water resistance and the friction contact area as well as accommodate lubricant. The lubrication theory model was established to predict the effect of geometric parameters of a biomimetic surface on tribological performance. The model has been proved to be feasible to predict tribological performance by the experimental results. The model was then used to investigate the effect of the grid textured surface on frictional performance of different geometries. The investigation was aimed at providing a rule for deriving the design parameters of a biomimetic surface with good lubrication characteristics. Results suggest that: (i) the increase in depression width ratio Λ decreases its corresponding coefficient of friction, and (ii) the small coefficient of friction is achievable when Λ is beyond 0.45. Superposition of depth ratio Γ and angle's couple under the condition of Λ < 0.45 affects the value of friction coefficient. It shows the decrease in angle decreases with the increase in dimension depth Γ.

scholarly journals <i>Brief communication</i> "A statistical validation for the cycles found in air temperature data using a Morlet wavelet-based method"

2010 ◽  
Vol 17 (3) ◽  
pp. 269-272 ◽  
Author(s):  
S. Nicolay ◽  
G. Mabille ◽  
X. Fettweis ◽  
M. Erpicum
Keyword(s):  
Air Temperature ◽  
Climate Model ◽  
Surface Air Temperature ◽  
Weather Forecast ◽  
Temperature Data ◽  
Temperature Time Series ◽  
Climatic Data ◽  
Statistical Validation ◽  
Confidence Levels ◽  
Temperature Time

Abstract. Recently, new cycles, associated with periods of 30 and 43 months, respectively, have been observed by the authors in surface air temperature time series, using a wavelet-based methodology. Although many evidences attest the validity of this method applied to climatic data, no systematic study of its efficiency has been carried out. Here, we estimate confidence levels for this approach and show that the observed cycles are significant. Taking these cycles into consideration should prove helpful in increasing the accuracy of the climate model projections of climate change and weather forecast.

Nonrelative sliding of spiral bevel gear mechanism based on active design of meshing line

2018 ◽  
Vol 233 (3) ◽  
pp. 1055-1067 ◽  
Author(s):  
Zhen Chen ◽  
Ming Zeng
Keyword(s):  
Design Method ◽  
Bevel Gear ◽  
Transmission Mechanism ◽  
Tooth Surface ◽  
Design Parameters ◽  
Spiral Bevel Gear ◽  
Bevel Gears ◽  
Gear Mechanism ◽  
Active Design ◽  
Spiral Bevel

In this paper, an active design method of meshing line for a spiral bevel gear mechanism with nonrelative sliding is presented. First, the general meshing line equations for a nonrelative sliding transmission mechanism between two orthogonal axes are proposed based on the active design parameters. Then, parametric equations for contact curves on the drive and driven spiral bevel gears are deduced by coordinate transformation of the meshing line equations. Further to this, parametric equations for the tooth surface of each bevel gear are derived according to the conical spiral motion of a generatrix circle along the calculated contact curves. Finally, a set of numerical examples is presented based on two types of motion equation of the meshing points. Material prototypes are fabricated and experimentally tested to validate the kinematic performance of the functionally designed spiral bevel gear set.

Sign in / Sign up

Export Citation Format

Share Document