Decision-making on choosing the type of strengthening of drains and upholstery ducts based on the ideal point method

2021 ◽  
pp. 57-62
Author(s):  
V. A. Podverbnyy ◽  
◽  
A. A. Perelygina ◽  

Modern materials and technologies for strengthening drainage and upland ditches, their advantages and disadvantages are considered. When choosing the type of reinforcement, the railway design engineer must compare the options for the types of reinforcement of ditches in terms of various criteria: reducing labour and resource intensity, duration of construction work, increasing durability, improving environmental friendliness, the need for special equipment, and others. An ideal point method is proposed for solving a multicriteria deterministic problem of choosing the type of ditch reinforcement. A prototype program of the decision support system for choosing the type of reinforcement using the ideal point method has been developed. The program contains four areas: the source data area; the calculation area; the guide to the types of ditch reinforcement, which separately identifies innovative types of ditch reinforcement; the area of calculation results and recommendations. With the help of the program, the test problem of choosing the type of reinforcement is solved. Of the three alternatives, a concrete roadbed is recommended-an innovative strengthening of the ditch.

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Yingchao Wang ◽  
Ning Zhao ◽  
Hongwen Jing ◽  
Bo Meng ◽  
Xin Yin

The classification of surrounding rock stability is the critical problem in tunneling engineering. In order to decrease engineering disasters, the surrounding rock stability should be accurately evaluated. The ideal point method is applied to the classification of surrounding rock stability. Considering the complexity of surrounding rock classification, some factors such as rock uniaxial compressive strengthen, integrality coefficient of rock mass, the angle between tunnel axis and the main joint, joints condition, and seepage measurement of groundwater are selected as evaluation indices. The weight coefficients of these evaluation indices are determined by the objective and subjective weighting method, consisting with the delphi method and the information entropy theory. The objective and subjective weighting method is exact and reliable to determine the weights of evaluation indices, considering not only the expert’s experiences, but also objectivity of the field test data. A new composite model is established for evaluating the surrounding rock stability based on the ideal point method and the objective and subjective weighting method. The present model is applied to Beigu mountain tunnel in Jiangsu province, China. The result is in good agreement with practical situation of surrounding rock, which proves that the ideal point method used to classify the surrounding rock in tunnels is reasonable and effective. The present model is simple and has very strong operability, which possesses a good prospect of engineering application.


1999 ◽  
Vol 5 (4) ◽  
pp. 285-289
Author(s):  
Edmundas K. Zavadskas ◽  
Leonas Ustinovičius

Quite frequently one has to solve variant synthesis multicriterial selection problems in construction. These problems consist of many technical-organisational solutions interacting with each other. The solution of each problem can be made of two or more alternatives. In each step k according to j, the effectiveness criterion is selected from variants i. Using the entropy method the weights of effectiveness indices in each step are calculated. By the criterion k(1) the effectiveness of variants in each step is determined. From the row of priorities obtained the first two variants are selected and they are repeatedly calculated by the same methods. The selection of variants (branches) synthesised is made by the criterion Ωs (2). A priority row of variants is determined according to the rule that the greater value of Ωsmeans the best variant (3). The second algorithm is used when there are more than two variants in the steps of problem. A joint matrix between separate steps of solutions is determined. Weights of criteria for each step are determined using the entropy method. It is necessary to regulate the values of importance according the number of variants. The weights obtained by the method of entropy are multiplied by the coefficient considering the number of alternatives analysed (4). The final valuation of branch is obtained according to the formula No 5. The best synthesis result is the one, having the largest Ωs value. The values of criteria effectiveness of each step of each net program branch are summed, when priorities are determined using the same coefficients of effectiveness. The weights are summed using formula 6. It is possible to calculate the priorities of alternatives using the ideal point method. The methods mentioned above were used to solve real life construction problems.


2018 ◽  
Vol 81 ◽  
pp. 382-390 ◽  
Author(s):  
Chen Xu ◽  
Xiaoli Liu ◽  
Enzhi Wang ◽  
Yanlong Zheng ◽  
Sijing Wang

2018 ◽  
Vol 28 (2) ◽  
pp. 901-911 ◽  
Author(s):  
Yingchao Wang ◽  
C. Guney Olgun ◽  
Linbing Wang ◽  
Bo Meng

Author(s):  
V. G. Titov ◽  
A. G. Zalazinsky ◽  
D. I. Kryuchkov ◽  
A. V. Nesterenko

The paper provides the results of an experimental study into the properties of compressed and sintered compacts of the following powders: VT-22 high-strength titanium alloy manufactured by plasma spraying of industrial titanium production waste, PTM-1 grade titanium manufactured by the hydrate-calcium method, and PV-N70Yu30 nickel-aluminum alloy. It was shown that charge composition selection for composite blank manufacturing is connected with the need to ensure optimization of several competing target functions. The relative density and strength of compacts under axial compression after sintering, as well as charge cost were chosen as optimization criteria. The problem was set and the method was proposed to select an optimal charge composition providing the necessary values of density, strength, as well as relatively low cost of products. The problem of multi-criteria optimization was solved based on the ≪ideal point≫ method. The results of calculations were compared with the previously obtained solutions of the problem under consideration using the Pareto method, linear programming, and generalized criterion. It was shown that different methods of multi-criteria optimization lead to significantly different results. In this case, the ≪ideal point≫ method gives the minimum discrepancy between the experimental and model values of the optimization criteria selected. The results of this study were used to create an expert system for the multi-criteria optimization of composite manufacturing processes. The charge composition obtained by the «ideal point» method was transferred to an industrial plant where an axially symmetric part was manufactured. The ultimate strength and relative density of the manufactured part material were in conformity with the predicted values.


Crystals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 887
Author(s):  
Chunhua Feng ◽  
Buwen Cui ◽  
Haidong Ge ◽  
Yihong Huang ◽  
Wenyan Zhang ◽  
...  

Recycled aggregate is aggregate prepared from construction waste. With the development of a global economy and people’s attention to sustainable development, recycled aggregate has shown advantages in replacing natural aggregate in the production of concrete due to its environmental friendliness, low energy consumption, and low cost. Recycled aggregate exhibits high water absorption and a multi-interface transition zone, which limits its application scope. Researchers have used various methods to improve the properties of recycled aggregate, such as microbially induced calcium carbonate precipitation (MICP) technology. In this paper, the results of recent studies on the reinforcement of recycled aggregate by MICP technology are synthesized, and the factors affecting the strengthening effect of recycled aggregate are reviewed. Moreover, the strengthening mechanism, advantages and disadvantages of MICP technology are summarized. After the modified treatment, the aggregate performance is significantly improved. Regardless of whether the aggregate was used in mortar or concrete, the mechanical properties of the specimens were clearly improved. However, there are some issues regarding the application of MICP technology, such as the use of an expensive culture medium, a long modification cycle, and untargeted mineralization deposition. These difficulties need to be overcome in the future for the industrialization of regenerated aggregate materials via MICP technology.


2019 ◽  
Vol 62 (4) ◽  
pp. 270-275
Author(s):  
O. S. Lekhov ◽  
A. V. Mikhalev ◽  
M. M. Shevelev

A comparative assessment of strenuous state of the anvils with and without channels has been carried out for the installation of combined continuous casting and deformation process in the production of steel sheets for welded pipes. The conditions of operation and loading of the anvils of combined continuous casting and deformation process are described. The design of anvil with channels for water cooling and the nature of its loading are given. Using the algorithm for solving problems in the elasticity theory by finite element method, the laws governing the distribution of axial stresses in anvils from the slab reduction force are determined. Effect of the channels for anvils cooling with water on the magnitude and nature of stresses distribution in them from the stress of the slab reduction was estimated. The calculation results of temperature fields and axial and equivalent thermoelastic stresses in anvils with channels are presented for the production process of steel sheets for welded pipes in a combined continuous casting and deformation unit. The article considers regularities of total stresses distribution in anvils with channels. To assess the effect of anvils structure on their stress state, regularities of distribution of thermoelastic and total stresses in strands without channels have been determined. The graph of dependence of thermoelastic stresses in the anvil on temperature of its contact surface is given. Recommendations for choosing the material of the fighters are given. The advantages and disadvantages of the anvils with channels for the unit for combined continuous casting and deformation are described. The parameters of such a pilot installation are presented. The authors also describe the results of an experimental study of the parameters of a combined process at the manufacture installation for continuous casting and deformation of JSC Ural Pipe Plant.


Sign in / Sign up

Export Citation Format

Share Document