This paper presents an analytical procedure for massive water-sealing barriers(MWSBs)that are made of partially overlapped jet-grouting columns used for deep excavations,in which two crucial factors of the permeabilit...This paper presents an analytical procedure for massive water-sealing barriers(MWSBs)that are made of partially overlapped jet-grouting columns used for deep excavations,in which two crucial factors of the permeability and strength of jet-grouted materials are considered.Subsequently,a calculation example is analyzed and discussed.Results show that“tension failure”mechanism is a major concern for the structural failure during a design of MWSBs.The maximum allowable seepage discharge is a crucial index for the design of MWSBs,which has a significant influence on determining the design parameters of MWSBs.Compared with the design procedure for MWSBs that is proposed in this paper,the design parameters of MWSBs determined by the stability equilibrium and seepage stability equilibrium approaches are conservative due to the fact that it fails to consider the permeability or strength of jet-grouted materials that makes a contribution to the structural safety.Based on the proposed design method,the ranges of both the thickness and depth of MWSBs for a case history of subway excavation in Fuzhou,China were determined.Finally,field pumping test results showed that the water-tightness performance of MWSBs performed at site was quite well.展开更多
This investigation and morphology analysis of porous structure of some kinds of natural materials such as chicken eggshell, partridge eggshell, pig bone, and seeds of mung bean, soja, ginkgo, lotus seed, as well as th...This investigation and morphology analysis of porous structure of some kinds of natural materials such as chicken eggshell, partridge eggshell, pig bone, and seeds of mung bean, soja, ginkgo, lotus seed, as well as the epidermis of apples, with SEM (Scanning Electronic Microscope) showed that natural structures’ pores can be classified into uniform pores, gradient pores and multi pores from the viewpoint of the distribution variation of pore density, size and geometry. Furthermore, an optimal design of porous bearings was for the first time developed based on the gradient configuration of natural materials. The bionic design of porous structures is predicted to be widely developed and applied in the fields of materials and mechanical engineering in the future.展开更多
Cherry is extremely perishable fruit and it needs to be dried in order to preserve the fruit for later uses. In this work, the influences of different osmotic solution concentrations on water loss （WL）, solid gain ...Cherry is extremely perishable fruit and it needs to be dried in order to preserve the fruit for later uses. In this work, the influences of different osmotic solution concentrations on water loss （WL）, solid gain （SG） and weight reduction （WR） during osmotic dehydration of cherry halves were investigated. These were studied using general factorial design with different sucrose concentrations （40, 55, 70%, w/v） and immersion time （5 hours）. Quadratic regression equations describing the effects of processes on WL, SG and WR were developed. The results revealed that the soaking time and sucrose concentration significantly （P 〈 0.05） influenced most of the quality indices of osmotically-dehydrated cherry halves. It is suggested that the regression equation obtained in this study can be used to find optimum conditions for osmotic dehydration.展开更多
This paper describes the use of a numerical and physical modelling study in the design of large breakwaters for a new port and dry dock complex on the southern coast of Oman. The numerical modelling was carried out to...This paper describes the use of a numerical and physical modelling study in the design of large breakwaters for a new port and dry dock complex on the southern coast of Oman. The numerical modelling was carried out to optimise the entrance channel layout with respect to wave penetration into the port and to refine design conditions for the sizing of the primary armour on the breakwaters. Wave conditions inside and outside of the port have been assessed using the 2-dimensional numerical wave penetration model MIKE21 EMS （Elliptic Mild-Slope）. As part of the design process, 3D physical modelling studies were also undertaken at Delft Hydraulics in the Netherlands to confirm the stability of the armour on the trunk and roundhead of the breakwaters and to verify the influence of the deep approach channel on stability. The opportunity was taken to extend the physical model tests to assess the influence of the deep channel on wave penetration through the port entrance. The paper focuses on the influence of the deep channel on wave conditions in the entrance to the port and compares the results from the numerical and physical modelling.展开更多
基金Projects(52090084, 51938008) supported by the National Natural Science Foundation of ChinaProject(2021T140474)supported by the China Postdoctoral Science Foundation。
文摘This paper presents an analytical procedure for massive water-sealing barriers(MWSBs)that are made of partially overlapped jet-grouting columns used for deep excavations,in which two crucial factors of the permeability and strength of jet-grouted materials are considered.Subsequently,a calculation example is analyzed and discussed.Results show that“tension failure”mechanism is a major concern for the structural failure during a design of MWSBs.The maximum allowable seepage discharge is a crucial index for the design of MWSBs,which has a significant influence on determining the design parameters of MWSBs.Compared with the design procedure for MWSBs that is proposed in this paper,the design parameters of MWSBs determined by the stability equilibrium and seepage stability equilibrium approaches are conservative due to the fact that it fails to consider the permeability or strength of jet-grouted materials that makes a contribution to the structural safety.Based on the proposed design method,the ranges of both the thickness and depth of MWSBs for a case history of subway excavation in Fuzhou,China were determined.Finally,field pumping test results showed that the water-tightness performance of MWSBs performed at site was quite well.
文摘This investigation and morphology analysis of porous structure of some kinds of natural materials such as chicken eggshell, partridge eggshell, pig bone, and seeds of mung bean, soja, ginkgo, lotus seed, as well as the epidermis of apples, with SEM (Scanning Electronic Microscope) showed that natural structures’ pores can be classified into uniform pores, gradient pores and multi pores from the viewpoint of the distribution variation of pore density, size and geometry. Furthermore, an optimal design of porous bearings was for the first time developed based on the gradient configuration of natural materials. The bionic design of porous structures is predicted to be widely developed and applied in the fields of materials and mechanical engineering in the future.
文摘Cherry is extremely perishable fruit and it needs to be dried in order to preserve the fruit for later uses. In this work, the influences of different osmotic solution concentrations on water loss （WL）, solid gain （SG） and weight reduction （WR） during osmotic dehydration of cherry halves were investigated. These were studied using general factorial design with different sucrose concentrations （40, 55, 70%, w/v） and immersion time （5 hours）. Quadratic regression equations describing the effects of processes on WL, SG and WR were developed. The results revealed that the soaking time and sucrose concentration significantly （P 〈 0.05） influenced most of the quality indices of osmotically-dehydrated cherry halves. It is suggested that the regression equation obtained in this study can be used to find optimum conditions for osmotic dehydration.
文摘This paper describes the use of a numerical and physical modelling study in the design of large breakwaters for a new port and dry dock complex on the southern coast of Oman. The numerical modelling was carried out to optimise the entrance channel layout with respect to wave penetration into the port and to refine design conditions for the sizing of the primary armour on the breakwaters. Wave conditions inside and outside of the port have been assessed using the 2-dimensional numerical wave penetration model MIKE21 EMS （Elliptic Mild-Slope）. As part of the design process, 3D physical modelling studies were also undertaken at Delft Hydraulics in the Netherlands to confirm the stability of the armour on the trunk and roundhead of the breakwaters and to verify the influence of the deep approach channel on stability. The opportunity was taken to extend the physical model tests to assess the influence of the deep channel on wave penetration through the port entrance. The paper focuses on the influence of the deep channel on wave conditions in the entrance to the port and compares the results from the numerical and physical modelling.
