American Journal of Civil Engineering最新文献

{"title":"The Finite Element Analysis of the Differential Settlement Prediction for the Adjacent Longitudinal Precast Box Culvert","authors":"Zenagebriel Gebremedhn, Jilong Li, Guofu Qiao","doi":"10.11648/J.AJCE.20190701.16","DOIUrl":"https://doi.org/10.11648/J.AJCE.20190701.16","url":null,"abstract":"This paper presents the finite element analysis of the differential settlement prediction for the adjacent longitudinal precast box culvert and subject to different loading conditions including different loading area. These culverts were investigated based on the finite element method was used to analyze the numerical solution of the problems under the condition of assembled of the standard three dimensional adjacent box culvert with beneath soil, side soil and floor reaction under different loading conditions and loading areas. It is located on right side soil of box culvert concerning to settlement which is using brick element in ABAQUS software. The culvert, floor reaction and soil were modeled using standard parameters of three dimensional solid geometric and material linearity. Finally, the settlement foundation was predicted using the finite element modeling and analysis, the screw bolt constraint is equivalent to the binding contact (tie constraint) so that the screw bolt connection has a negative impact on the performance of the side wall of adjacent longitudinal box culvert specifically if there is a settlement occurred.","PeriodicalId":7606,"journal":{"name":"American Journal of Civil Engineering","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77493329","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rules Regulating the Change in Physiological Parameters of Rats Under Simulated Microgravity and Different Ambient Temperatures","authors":"Jie Qian, Gengxin Xie, Jie Zheng, Bo Duan, Yajun Cao, Xi Wang, Fengjie Li, Changpeng Hu","doi":"10.11648/J.AJCE.20190701.15","DOIUrl":"https://doi.org/10.11648/J.AJCE.20190701.15","url":null,"abstract":"To investigate the rules regulating changes in mean chest temperature (MCT), mean rectal temperature (MRT) and mean body weight (MW)in rats at simulated microgravity and different ambient temperatures (ATs). The −30o rat tail suspension (TS) method was used to simulate microgravity over a 7 day period at 18°C, 20°C, 23°C and 26°C AT through comparison between the TS group and control group. Each group contained six male SD rats (including one verification rat). MCT and MRT of TS group rats increased at all four levels of AT. MCT and MRT reached maximum growth rates of 0.315 and 0.118 at ATs of 20°C and 23°C, respectively. MW was reduced at ATs of 20°C and 23°C, whereas it increased at 18°C and 26°C AT in the TS group. The rates of changes of MCT, MRT and MW at different ATs were analyzed using linear regression analysis for both the control (Equation 1) and TS (Equation 2) groups. Using A new equation (Equation 3) without the influence of other factors was derived after Equation 1 minus Equation 2 to derive. The result shows that the coefficients of Equation 3 are different under the four ATs. TS and AT have coupling effects on the MCT, MRT and MW of rats.","PeriodicalId":7606,"journal":{"name":"American Journal of Civil Engineering","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79151445","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Production of Lightweight Concrete Using Corncob Ash as Replacement of Cement in Concrete","authors":"Sintayehu Assefa, Mamaru Dessalegn","doi":"10.11648/J.AJCE.20190701.13","DOIUrl":"https://doi.org/10.11648/J.AJCE.20190701.13","url":null,"abstract":"One of the biggest issues, all over the world is getting affordable house to the community. In developing countries, where it is difficult for most people to satisfy basic needs, construction of modern house is a big challenge. Different ways were tried by researchers and scholars to find alternative construction materials. One of this is replacing the costly construction material of cement with locally available material, especially with those considered as waste. Corncob is an agricultural waste, which is considered as one of binding materials. Very few researchers tried to use corncob ash as a means of producing lightweight concrete. So, this research was aimed to check whether corncob ash is used to produce lightweight concrete by replacing cement as a binding material or not. In order to reach on conclusion, corncob was collected from agricultural farmers and burned in furnace at a temperature of 850°C. The burned ash powder was sieved in order to remove coarser material and replacement of cement was done by 5%, 10%, 15%, 20%, 25%, 30%, and 35% with corncob ash. For each replacement, including control, 3 samples were prepared based on ASTM standards. After curing for 7 and 28 days in curing tank, the weight and compressive strength of samples were checked. Based on the experimental result, as the percentage of corncob ash increase, the weight of cubes decreased and 15% and above corn cob ash replacement makes concrete cubes lightweight. The compressive strength was also decreasing as the amount of replacement increase. However, up to 15% replacement, compressive strength is found within the range of concrete grade requirement.","PeriodicalId":7606,"journal":{"name":"American Journal of Civil Engineering","volume":"40 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85218454","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of a Self-balanced Rock True Triaxial Compression Instrument","authors":"Tang Yanchun, Wang Yue, Liu Ruilong, Zhou Hui, Mao Qingfeng","doi":"10.11648/J.AJCE.20190701.12","DOIUrl":"https://doi.org/10.11648/J.AJCE.20190701.12","url":null,"abstract":"Based on the analysis of the structure and the performance of similar instruments at home and abroad, a Self-balanced Rock True Triaxial Compression instrument (SRT) was developed. For SRT, complex stress realization, based on three-dimensional stress alone control and change; and the self-balanced structure is adopted on the basis of frame design, which makes the instrument simple and compact; design of lateral composite press plate with embedded rolling roller, the influence of test results on the effect of friction on the side end surface of the specimen under lateral stress constraint can be eliminate effectiveness; The design scheme of transverse double sliding rod is adopted, its validity can be designed by horizontal alignment, and the problem of eccentric compression of specimen can be partly alleviated in horizontal direction. By changing the alkali of the mothed triaxial chamber, both true triaxial and conventional triaxial compression can be tested. Test results of true triaxial and conventional compression of rocks with different lithology were carried out by SRT. The results, such as the deformation and failure characteristics of rock strength in complex stress conditions, have been obtained by SRT, which indicates that the design of SRT is feasible and feasible. The development of this instrument can promote the further development of Chinese rock triaxial testing machine.","PeriodicalId":7606,"journal":{"name":"American Journal of Civil Engineering","volume":"20 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83331309","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Concept of Value Engineering and Current Project Management Practice in Ethiopian Building Construction Projects","authors":"Tsigereda Garomsa, Elmer C. Agon, Sintayehu Assefa","doi":"10.11648/j.ajce.20190701.11","DOIUrl":"https://doi.org/10.11648/j.ajce.20190701.11","url":null,"abstract":"In construction projects, when one-program costs more than planned, decision makers are forced to delay or cancel other activity. Value Engineering can play a key role in overcoming such problems by ensuring programs stay within project duration, estimated budget and saving costs. This study was conducted to assess the applicability of value engineering concept and the current management practice of Ethiopian building construction projects. In this study, knowhow of Ethiopian building construction project experts on value engineering principles were studied and the current management practice was examined. In order to gather required information, questionnaire, interview with project managers and archival review was conducted. Data was analyzed both qualitatively and quantitatively. The result of this study shows, main challenges in the project area were: delay in progress payment by owner, poor site management, weak follow up by consultant, and delay in material delivery from contractor side. Almost all experts in the project have no knowledge on the principle of value engineering and has no willingness to implement the principle. The evaluation made using value engineering principle shows the current management practice was more conventional and the industry is still facing delay of projects, cost overrun and poor quality while there are opportunities to minimize such problems.","PeriodicalId":7606,"journal":{"name":"American Journal of Civil Engineering","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85857322","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Highway Asset Management Framework for Longevity of Infrastructure – A Case Study for China-Pakistan Economic Corridor","authors":"Muhammad Irfan, Y. Mehmood, Anwaar Ahmed, Hainian Wang","doi":"10.11648/j.ajce.20180606.12","DOIUrl":"https://doi.org/10.11648/j.ajce.20180606.12","url":null,"abstract":"Pavement management system (PMS) affords objective information and useful data analysis to make consistent, cost-effective, and defensible decisions related to the pavement preservation at network and project level. Pavement functional and structural evaluations using performance indicators such as international roughness index (IRI), surface distress, rutting, deflection data etc. are the key element of PMS. A departure from exiting stand-alone evaluation practices, this research presents project-level functional and structural evaluation and its integration into a PMS framework for more accurate and realistic forecasting of the pavement needs over the analysis period. A case study of an in-service pavement is presented to demonstrate the applicability of proposed framework. Owing to the non-availability of time-series performance data at present, pavement serviceability and structural capacity data before and after of an in-service pavement rehabilitation was explored for overlay treatments (conventional and crumb rubber- modified (CRM) asphalt mixtures) effectiveness analyses. Results of functional evaluation quantified the extent to which CRM improves the functional performance of the pavement, in terms of the drop in IRI. CRM asphalt mixture exhibited relatively superior functional performance in contrast to conventional asphaltic wearing course by a margin of 8% higher drop in IRI, on average. Non-destructive testing technique for pavement structural evaluation using falling weight deflectometer (FWD) data was employed to assess structural capacity of pavements. A computer-aided program was developed for estimation of structure number effective (SNeff) to be used as an input for overlay design using AASHTO empirical method. Moreover, mechanistic-empirical (M-E) design method was employed using evaluation of layer moduli and overlay design (ELMOD) program for overlay thickness design and pavement remaining service life (RSL). Comparison of pre- and post-rehabilitation deflection data endorsed roadbed soil stiffness and structural adequacy. RSL estimated through traffic data (truck load repetitions) validated the results obtained using empirical and M-E methods. Application of KENPAVE program for evaluation of pavement overlay thickness design was also demonstrated by conducting damage analysis. Integrating structural evaluation with functional evaluation into an overall framework of PMS is envisaged to provide systematic and objective procedures for monitoring and evaluating pavement performance, selecting optimal type of treatment and its thickness design.","PeriodicalId":7606,"journal":{"name":"American Journal of Civil Engineering","volume":"7 1","pages":"185"},"PeriodicalIF":0.0,"publicationDate":"2019-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78516564","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Logistic Model Predicting Occurrence Probability of Debris Flow","authors":"J. P. Wang","doi":"10.11648/j.ajce.20190701.14","DOIUrl":"https://doi.org/10.11648/j.ajce.20190701.14","url":null,"abstract":"","PeriodicalId":7606,"journal":{"name":"American Journal of Civil Engineering","volume":"153 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74692038","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improvement of Strength and Consolidation Properties of Clayey Soil Using Ceramic Dust","authors":"Md. Akhtar Hossain","doi":"10.11648/j.ajce.20190702.11","DOIUrl":"https://doi.org/10.11648/j.ajce.20190702.11","url":null,"abstract":"","PeriodicalId":7606,"journal":{"name":"American Journal of Civil Engineering","volume":"44 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79957422","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Expanding Understanding on Attributes of Innovation Champions: Firms and Individual Perspectives of Professional Quantity Surveying Firms","authors":"Owusu-Manu De Graft, A. Prince, Edwards David John","doi":"10.11648/J.AJCE.20180606.11","DOIUrl":"https://doi.org/10.11648/J.AJCE.20180606.11","url":null,"abstract":"Quantity Surveying Profession (QSP) globally has undergone significant revolution and has embraced career pathways in providing excellent services within and outside the construction industry. The QSP adapting to the changes in the construction industry, and innovating to remain competitive has allowed them to adopt some specific attributes which makes them process innovation champions. Identifying these characteristics of the QSP for appreciation and implementation gave the purpose for this studies. Drawing from quantitative research approach, and using purposive and convenience sampling technique, data was collected and analysed. The study adopted descriptive statistics, Relative Importance Index (RII) and cross tabulations as its tools of analysis. After analysis, the outstanding attribute of innovative Quantity Surveying (QS) firms’ worthy of emulation were good managerial skills and capability, followed by team learning and competency. On individual perspective, all the identified variables were outstanding characteristics with interaction with others in the workplace ranking first, followed by open to experience while acting out of curiosity ranked last. Findings of this study could assist in understanding the set of characteristics which makes firms innovative. The identified attributes would also help other project teams in the construction industry to increase their innovativeness and output when they are examined, understood and implemented.","PeriodicalId":7606,"journal":{"name":"American Journal of Civil Engineering","volume":"40 3 1","pages":"178"},"PeriodicalIF":0.0,"publicationDate":"2018-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78012434","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seismic Response Evaluation of High-Rise Building with and Without Fluid Viscous Damper","authors":"Khalil Yahya Mohammed Almajhali, Bin Xu, Qingxuan Meng","doi":"10.11648/j.ajce.20180605.15","DOIUrl":"https://doi.org/10.11648/j.ajce.20180605.15","url":null,"abstract":"The major lateral load of the high structures is the earthquake load. In the high rise buildings, the structural response increases exponentially in response to earthquake load. Therefore, the damping has significant function in design of Earthquake Resistant High Structures, which can decrease the response of the structure when exposed to lateral loads. The energy produced by earthquake will be absorbed by these devices and the load acting on the main structure of the building will reduce significantly. The fluid viscous dampers are used to dissipate energy and lessen the response of reinforced concrete buildings. The main function of structure is to carry the lateral loads and transmit them well to the foundation. The lateral loads enjoined on the structures are dynamic in nature, which cause vibrations in the structure. In the current study, the responses of the structures having square plans with different cross-sections are analyzed by the software ETABS 2015 based on the consideration of Fluid Viscous Damper. The results of numerical examples show that fluid viscous damper (250) can reduce the response of the structures effectively, including the base shear of the buildings, and the structures with square columns performs perfect and have good earthquake resistant characteristics when compared to structures with rectangular columns regardless of the flooring plan.","PeriodicalId":7606,"journal":{"name":"American Journal of Civil Engineering","volume":"93 1","pages":"167"},"PeriodicalIF":0.0,"publicationDate":"2018-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76119247","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}