The complexity of near surface intensifies the diversity of seismic wave fields,which makes study on near surface wavefields important in many aspects.The strong absorption of low velocity layer can affect the resolut...The complexity of near surface intensifies the diversity of seismic wave fields,which makes study on near surface wavefields important in many aspects.The strong absorption of low velocity layer can affect the resolution of seismic data,and free boundary can cause surface wave.Considering the above problems, we focus on the Rayleigh wavefields simulation using finite-difference wave equation of higher-order staggered grids and PML boundary conditions.Free boundary,buried source and overlying low velocity layer are taken into consideration and point explosion source is adopted.Through some numerical simulation with different parameters,we quantitatively analyze relationship between wave intensity and source depth,as well as the energy variation with propagation and obtain some practical knowledge and conclusions.展开更多
This paper presents a focused study on using different methods to enhance the ultimate capacity of flexural behavior in RC slabs. Four RC specimens were casted with common compressive strength and reinforced with stee...This paper presents a focused study on using different methods to enhance the ultimate capacity of flexural behavior in RC slabs. Four RC specimens were casted with common compressive strength and reinforced with steel mesh. Specimens were strengthened with different methods such as usage of GFRP sheets, carbon fibers laminate strips and near surface mounted steel rebars. All specimens were subjected to two-point loading setup. Load was increased from zero to failure load. First crack was recorded and crack pattern was observed. The behavior of strengthened specimens was compared to that of the control specimen to judge the efficiency of the used techniques. Test results showed that the used techniques were effective in enhancing the behavior of the strengthened slabs by noteworthy values.展开更多
基金support of the Major National Science and Technology Projects(No.2011ZX05006-002)the Fundamental Research Funds for the Central Universities of China(No.09CX04009A)
文摘The complexity of near surface intensifies the diversity of seismic wave fields,which makes study on near surface wavefields important in many aspects.The strong absorption of low velocity layer can affect the resolution of seismic data,and free boundary can cause surface wave.Considering the above problems, we focus on the Rayleigh wavefields simulation using finite-difference wave equation of higher-order staggered grids and PML boundary conditions.Free boundary,buried source and overlying low velocity layer are taken into consideration and point explosion source is adopted.Through some numerical simulation with different parameters,we quantitatively analyze relationship between wave intensity and source depth,as well as the energy variation with propagation and obtain some practical knowledge and conclusions.
文摘This paper presents a focused study on using different methods to enhance the ultimate capacity of flexural behavior in RC slabs. Four RC specimens were casted with common compressive strength and reinforced with steel mesh. Specimens were strengthened with different methods such as usage of GFRP sheets, carbon fibers laminate strips and near surface mounted steel rebars. All specimens were subjected to two-point loading setup. Load was increased from zero to failure load. First crack was recorded and crack pattern was observed. The behavior of strengthened specimens was compared to that of the control specimen to judge the efficiency of the used techniques. Test results showed that the used techniques were effective in enhancing the behavior of the strengthened slabs by noteworthy values.
