http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Hossein Hosseinjanzadeh (검색결과 2 건)
- 무료
- 기관 내 무료
- 유료
-
Hojat Karami,Hossein Hosseinjanzadeh,Khosrow Hosseini,Abdollah Ardeshir 대한토목학회 2018 KSCE JOURNAL OF CIVIL ENGINEERING Vol.22 No.1
Installing collar on abutment is an applicable method to protect the abutment against scouring. In this study, effect of using collar on reduction of scour depth at short vertical-wall abutment (ratio of abutment length to flow depth of less than 1, La/y < 1) under clear-water conditions and uniform bed materials was investigated experimentally. Different sizes and various elevations of installing collar were studied. Results showed that using collar with 2.25La in width, situated under the bed elevation, led to 88.9% scour depth reduction for threshold flow condition. Three-dimensional velocity components around the abutment, for both with/without collar conditions, were measured by Acoustic Doppler Velocimeter (ADV). Turbulent intensity components, Reynolds stresses and bed shear stress on a rough rigid bed were studied at different sections. A primary vortex, associated with the downflow, existed at upstream face of the abutment. In the downstream, the flow field was turbulent due to the vortex shedding, and wake vortices occurred near the bed level next to the abutment. Installing collar led to diminish the vortex power below the collar. Also, turbulent intensity at upstream face of the abutment and dimensionless shear stress was reduced by using collar. The data presented in this paper could be useful for development and validation of a flow field model.
-
Khosrow Hosseini,Hojjat Karami,Hossein Hosseinjanzadeh,Abdollah Ardeshir 대한토목학회 2016 KSCE JOURNAL OF CIVIL ENGINEERING Vol.20 No.5
Maximum depth of scouring around bridge abutments is a significant criterion in design of safe depth for abutment foundation. Many studies done on maximum scouring depth are limited to specific shape of abutment and there is no general equation in the estimation of time varying scour depth at short abutments. In this research, maximum depth and also the temporal variation of local scour at a vertical-wall, wing-wall and semicircular abutments, and spur dike as well, were investigated experimentally. About 1400 sets of experimental data were collected. The results indicated that 70-90% of the equilibrium scouring depths occurred during the first 20% of overall time of scouring tests. According to the collected data, Multiple Nonlinear Regression (MNLR), Artificial Neural Networks (ANN) and Adaptive Neuro Fuzzy Inference System (ANFIS) were adopted to predict the time variation of scour depth around abutments. The computer models were compared to the other empirical equations presented in the literature. The study showed that the conducted regression model is rather precise and practical (R2 = 0.88). Also, the results of the numerical modeling indicated that ANFIS model produced the best results (R2 = 0.98) in comparison with ANN models using feed forward back propagation (R2=0.96) and radial basis function (R2 = 0.94).
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
