Effect of Boundary Conditions on the Mechanical Behavior of the Geogrid–Soil Interface

Geogrid-reinforced structures are extensively adopted in various engineering fields. At present, the influence of boundary conditions was not considered in design methods, bringing hidden dangers to the safety of the structure. In the current study, a series of pullout tests were carried out on high-density polyethylene (HDPE) geogrid-reinforced coarse sand. The magnitude and growth pattern of pullout resistance and the variation laws of interfacial shear strength indexes under four types of boundary conditions were analyzed. Additionally, the boundary reduction coefficient (BRC) was introduced to establish the relationship between rigid and flexible boundary for the design of the structure. The tests results showed that the boundary conditions cannot be ignored in the design of structures, especially in the front. When the normal loading was up to 120 kPa, the BRC-top and BRC-positive could be taken as 0.9 and 0.5, respectively, and verified by fitting results. The boundary conditions affected the pullout resistance, while the vertical loading corresponding to the maximum pullout resistance was not related to boundary conditions. Investigating the interaction of the geogrid–soil under different boundary conditions can help to improve the understanding of the behavior of reinforced soil structure, and to achieve a more efficient and economical design.

Calculating Feeder Fault Current with MATLAB Software Program

The aim of this article describes the program of computerized how to calculate the feeder fault current in a distribution substation. This article adopts Thevenin theory as the basis of calculation, and narrates them in two ways: the artificial and the computerized algorithm. It leaves aside the artificial and delves the computerized algorithm. The latter is divided for two computerized algorithm - separate and all of equipment. In the computerized algorithm, all data inputting, procedure steps, and report form were carefully been designed by MATLAB application software. As for data Inputting refers to the specification parameters of equipment component. The characteristics of this article are described with both text and Fig. to achieve operation simple and understanding easy. References include a representative textbook and several journal articles. Verify with real cases and reveal the pros and cons of artificial and program algorithms. The purpose of this article is to discard waste - an artificial calculation that is time - consuming, cumbersome and prone to clerical errors. The computer programs algorithm can compensates for defects and improves accuracy and timeliness. This method has been proven to be an economical design aid tool that is of great help to maintenance or designers in the field of electrical engineering.

Probabilistic Design of Retaining Wall Using Machine Learning Methods

Retaining walls are geostructures providing permanent lateral support to vertical slopes of soil, and it is essential to analyze the failure probability of such a structure. To keep the importance of geotechnics on par with the advancement in technology, the implementation of artificial intelligence techniques is done for the reliability analysis of the structure. Designing the structure based on the probability of failure leads to an economical design. Machine learning models used for predicting the factor of safety of the wall are Emotional Neural Network, Multivariate Adaptive Regression Spline, and SOS–LSSVM. The First-Order Second Moment Method is used for calculating the reliability index of the wall. In addition, these models are assessed based on the results they produce, and the best model among these is concluded for extensive field study in the future. The overall performance evaluation through various accuracy quantification determined SOS–LSSVM as the best model. The obtained results show that the reliability index calculated by the AI methods differs from the reference values by less than 2%. These methodologies have made the problems facile by increasing the precision of the result. Artificial intelligence has removed the cumbersome calculations in almost all the acquainted fields and disciplines. The techniques used in this study are evolved versions of some older algorithms. This work aims to clarify the probabilistic approach toward designing the structures, using the artificial intelligence to simplify the practical evaluations.

Experimental study on web crippling of lapped cold-formed steel channels subjected to interior two-flange loading

The current North American Specifications for the Design of Cold-Formed Steel (CFS) Structural Members, AISI-S136-01, specifies expressions for web crippling strength of different joist geometries in case of exterior end and concentrated load locations. However, it does not permit an in increase two-flange loading. Thus, the objective of this research in this thesis is to generate experimental data for CFS channels where both webs of channel members are lapped at the interior support location and being loaded simultaneously. This thesis summarizes the results of a parametric study to examine few parameters that affect web crippling strength of such lapped channels. These parameters include the unbraced length of channel member, the presence screws, the level of flange restraint at the interior support location, channel six and load bearing length (i.e. lap length). Test specimens were loaded to failure and load history and the failure pattern were recorded. Based on experimental findings, a reliable and economical design expression was developed for web crippling strength of lapped CFS channels at interior support location when subjected to two-flange loading.

Experimental study on web crippling of lapped cold-formed steel channels subjected to interior two-flange loading

The current North American Specifications for the Design of Cold-Formed Steel (CFS) Structural Members, AISI-S136-01, specifies expressions for web crippling strength of different joist geometries in case of exterior end and concentrated load locations. However, it does not permit an in increase two-flange loading. Thus, the objective of this research in this thesis is to generate experimental data for CFS channels where both webs of channel members are lapped at the interior support location and being loaded simultaneously. This thesis summarizes the results of a parametric study to examine few parameters that affect web crippling strength of such lapped channels. These parameters include the unbraced length of channel member, the presence screws, the level of flange restraint at the interior support location, channel six and load bearing length (i.e. lap length). Test specimens were loaded to failure and load history and the failure pattern were recorded. Based on experimental findings, a reliable and economical design expression was developed for web crippling strength of lapped CFS channels at interior support location when subjected to two-flange loading.

Seismic Performance of Elevated Reinforced Concrete Water Tanks

Most of the codal provisions used worldwide for the design of elevated water tanks incorporates the nonlinear response through reduction factor that considers overstrength, ductility and redundancy. The majority of these codes provide a value which incorporates the demand of their geological condition and construction industry. In Nepal, there is lack of own guidelines and codes for the seismic design of elevated water tanks. In the present work, seismic performance of elevated reinforced concrete (RC) Intze type water tank is evaluated and value of the response reduction factor (R) for the design of such tank is determined. In this research work 34 models of elevated reinforced water tank were analyzed using SAP 2000 to evaluate the seismic performance with varying tank filling condition and staging height for 450 cumec and 225 cumec capacity. Based on the results, it is concluded that single value of response reduction factor cannot be justified for all heights and capacity of elevated RC water tank. So, for economical design purpose, estimation of response reduction factor with exact analysis is preferred.