The deformation, of embankment has serious influences on neighboring structure and infrastructure. A trial embankment is reanalyzed by elastoplastic damage model coupling Blot＇ s consolidation theory. With the increa...The deformation, of embankment has serious influences on neighboring structure and infrastructure. A trial embankment is reanalyzed by elastoplastic damage model coupling Blot＇ s consolidation theory. With the increase in time of loading, the damage accumulation becomes larger. Under the centre and toe of embankment, damage becomes serious. Under the centre of embankment, vertical damage values are bigger than horizontal ones. Under the toe of embankment, horizontal damage values are bigger than vertical ones.展开更多
This paper presents an analytical solution for one-dimensional consolidation of soft soil under some common types of cyclic loading such as trapezoidal cyclic loading, based on the assumptions proposed by Davis and Ra...This paper presents an analytical solution for one-dimensional consolidation of soft soil under some common types of cyclic loading such as trapezoidal cyclic loading, based on the assumptions proposed by Davis and Raymond （1965） that the decrease in permeability is proportional to the decrease in compressibility during the consolidation process of the soil and that the distribution of initial effective stress is constant with depth the solution obtained, some diagrams are prepared and the It is verified by the existing analytical solutions in special cases. Using telex ant consolidation behavior is investigated.展开更多
The problem of a rigid disk acting with normal force on saturated soil was studied using Biot consolidation theory and integral equation method and the Merchant model to describe the saturated soil rheology. Using int...The problem of a rigid disk acting with normal force on saturated soil was studied using Biot consolidation theory and integral equation method and the Merchant model to describe the saturated soil rheology. Using integral transform techniques, general solutions of Biot consolidation functions and the dual integral equations of a rigid disk on saturated soil were established based on the boundary conditions. These equations can be simplified using Laplace-Hankel and Abel transform methods. The numerical solutions of the integral equations, and the corresponding inversion transform were used to obtain the settlement and contact stresses of the rigid disk. Numerical examples showed that the soil settlement is small if only consolidation is considered, so the soil rheology must be taken into account to calculate the soil settlement. Numerical solution of Hankel inverse transform is also given in this paper.展开更多
Deformation characteristics of light weight soil with different EPS (expanded polystyrene) sizes were investigated by consolidation tests.The results show that the confined stress-strain relation curve is in S shape,w...Deformation characteristics of light weight soil with different EPS (expanded polystyrene) sizes were investigated by consolidation tests.The results show that the confined stress-strain relation curve is in S shape,which has a good homologous relation with e-p curve and e-lgp curve,and three types of curves reflect obvious structural characteristics of light weight soil.When cement mixed ratio and EPS volume ratio are the same for different specimens,structural strength decreases with the increase of EPS size,but compressibility indexes basically keep unchanged within the structural strength.The settlement of light weight soil can be divided into instantaneous settlement and primary consolidation settlement.It has no obvious rheology property,and 90% of total consolidation deformation can be finished in 1 min.Settlement-time relation of light weight soil can be predicted by the hyperbolic model.S-lgt curve of light weight soil is not in anti-S shape.It is proved that there is no secondary consolidation section,so consolidation coefficient cannot be obtained by time logarithm method.Structural strength and unit price decrease with the increase of EPS size,but the reducing rate of the structural strength is lower than that of the unit price,so the cost of mixed soil can be reduced by increasing the EPS size.The EPS beads with 3-5 mm in diameter are suggested to be used in the construction process,and the prescription of mixed soil can be optimized.展开更多
The prediction of embankment settlement is a critically important issue for the serviceability of subgrade projects,especially the post-construction settlement.A number of methods have been proposed to predict embankm...The prediction of embankment settlement is a critically important issue for the serviceability of subgrade projects,especially the post-construction settlement.A number of methods have been proposed to predict embankment settlement;however,all of these methods are based on a parameter,i.e.the initial time point.The difference of the initial time point determined by different designers can de?nitely induce errors in prediction of embankment settlement.This paper proposed a concept named"potential settlement"and a simpli?ed method based on the in situ data.The key parameter"b"in the proposed method was veri?ed using theoretical method and?eld data.Finally,an example was used to demonstrate the advantages of the proposed method by comparing with other methods and the observation data.展开更多
In order to analyze the influence of replacement depth of black cotton soil(BCS)foundation on the initial cracking depth of a highway embankment,the laboratory tests were performed to construct the constitutive relati...In order to analyze the influence of replacement depth of black cotton soil(BCS)foundation on the initial cracking depth of a highway embankment,the laboratory tests were performed to construct the constitutive relationship between state variables and stress variables of BCS,and the coupled consolidation theory for unsaturated soils was employed to simulate the change in the major principal stress of the subgrade soils caused by water loss shrinkage of BCS with the help of Abaqus 6.11 codes.The simulation results indicate that the water losing shrinkage of BCS causes tensile stress within the subgrade,which leads to embankment cracking.The crack depth decreases with the increase in the BCS replacement depth and the embankment height,and increases with the increase in the burial depth of BCS.In the distribution area of deep BCS,the key values of foundation replacement depth for controlling the crack depth of the embankment with the height of 1 to 4 m are 1.2 and 1.5 m.In the low filling section,when the buried depth of BCS is 2,3 and 4 m,the key values of the foundation replacement depth to control the crack depth of the embankment are 0.8 and 1.2 m.In order to control the embankment cracking induced by the water losing shrinkage of BCS,a reasonable replacement depth of the foundation should be selected while slope protection is carried out well.展开更多
Because there are plenty of clay particles in the flush fluid of Pingguo Aluminum Mine, the consolidationtechnology in geotechnical engineering was adopted to carry out the disassociation of water and soil disassociat...Because there are plenty of clay particles in the flush fluid of Pingguo Aluminum Mine, the consolidationtechnology in geotechnical engineering was adopted to carry out the disassociation of water and soil disassociation. Inthis method, vacuum method, electro-osmosis and chemical flocculation were used comprehensively to separate soilfrom flush fluid. The experiments of the method of "vacuum + electro-osmosis" for drainage was made. After pretreat-ing the flush fluid, suction pressure was offered by the sand well in the bottom and electro-osmosis was used to drainoff water. The results of the experiment show that the good effect can be obtained in drainage when the electric gradi-ent is greater than 8.3 V/cm and the quantity of sand well is more than 6. In industrial production, it is necessary to in-crease the quantity of sand well, to arrange the electrodes rationally and to set up an intermittent electric circuit. On thebasis of the experiments , the industrial feasible flow was put forward. It may be a helpful attempt to apply consolida-tion technology to the fields of the environmental protection and so on.展开更多
文摘The deformation, of embankment has serious influences on neighboring structure and infrastructure. A trial embankment is reanalyzed by elastoplastic damage model coupling Blot＇ s consolidation theory. With the increase in time of loading, the damage accumulation becomes larger. Under the centre and toe of embankment, damage becomes serious. Under the centre of embankment, vertical damage values are bigger than horizontal ones. Under the toe of embankment, horizontal damage values are bigger than vertical ones.
基金Projects supported by the National Research Foundation for theDoctoral Program of Higher Education of China (No. 20030335027)and the Natural Science Foundation of Zhejiang Province (No.Y104463), China
文摘This paper presents an analytical solution for one-dimensional consolidation of soft soil under some common types of cyclic loading such as trapezoidal cyclic loading, based on the assumptions proposed by Davis and Raymond （1965） that the decrease in permeability is proportional to the decrease in compressibility during the consolidation process of the soil and that the distribution of initial effective stress is constant with depth the solution obtained, some diagrams are prepared and the It is verified by the existing analytical solutions in special cases. Using telex ant consolidation behavior is investigated.
文摘The problem of a rigid disk acting with normal force on saturated soil was studied using Biot consolidation theory and integral equation method and the Merchant model to describe the saturated soil rheology. Using integral transform techniques, general solutions of Biot consolidation functions and the dual integral equations of a rigid disk on saturated soil were established based on the boundary conditions. These equations can be simplified using Laplace-Hankel and Abel transform methods. The numerical solutions of the integral equations, and the corresponding inversion transform were used to obtain the settlement and contact stresses of the rigid disk. Numerical examples showed that the soil settlement is small if only consolidation is considered, so the soil rheology must be taken into account to calculate the soil settlement. Numerical solution of Hankel inverse transform is also given in this paper.
基金Project(2012JQ7013)supported by the Natural Science Foundation of Shaanxi Province,ChinaProject(QN2012025)supported by the Fundamental Research Funds for the Central Universities of ChinaProject(2011BSJJ084)supported by Research Foundation of Northwest A&F University,China
文摘Deformation characteristics of light weight soil with different EPS (expanded polystyrene) sizes were investigated by consolidation tests.The results show that the confined stress-strain relation curve is in S shape,which has a good homologous relation with e-p curve and e-lgp curve,and three types of curves reflect obvious structural characteristics of light weight soil.When cement mixed ratio and EPS volume ratio are the same for different specimens,structural strength decreases with the increase of EPS size,but compressibility indexes basically keep unchanged within the structural strength.The settlement of light weight soil can be divided into instantaneous settlement and primary consolidation settlement.It has no obvious rheology property,and 90% of total consolidation deformation can be finished in 1 min.Settlement-time relation of light weight soil can be predicted by the hyperbolic model.S-lgt curve of light weight soil is not in anti-S shape.It is proved that there is no secondary consolidation section,so consolidation coefficient cannot be obtained by time logarithm method.Structural strength and unit price decrease with the increase of EPS size,but the reducing rate of the structural strength is lower than that of the unit price,so the cost of mixed soil can be reduced by increasing the EPS size.The EPS beads with 3-5 mm in diameter are suggested to be used in the construction process,and the prescription of mixed soil can be optimized.
基金a part of the project "Universities Natural Science Research Project in Anhui Province" (KJ2011Z375)supported by Department of Education of Anhui Province
文摘The prediction of embankment settlement is a critically important issue for the serviceability of subgrade projects,especially the post-construction settlement.A number of methods have been proposed to predict embankment settlement;however,all of these methods are based on a parameter,i.e.the initial time point.The difference of the initial time point determined by different designers can de?nitely induce errors in prediction of embankment settlement.This paper proposed a concept named"potential settlement"and a simpli?ed method based on the in situ data.The key parameter"b"in the proposed method was veri?ed using theoretical method and?eld data.Finally,an example was used to demonstrate the advantages of the proposed method by comparing with other methods and the observation data.
基金The National Natural Science Foundation of China(No.51778139)the Construction System Science and Technology Project of Jiangsu Province(No.2019ZD058).
文摘In order to analyze the influence of replacement depth of black cotton soil(BCS)foundation on the initial cracking depth of a highway embankment,the laboratory tests were performed to construct the constitutive relationship between state variables and stress variables of BCS,and the coupled consolidation theory for unsaturated soils was employed to simulate the change in the major principal stress of the subgrade soils caused by water loss shrinkage of BCS with the help of Abaqus 6.11 codes.The simulation results indicate that the water losing shrinkage of BCS causes tensile stress within the subgrade,which leads to embankment cracking.The crack depth decreases with the increase in the BCS replacement depth and the embankment height,and increases with the increase in the burial depth of BCS.In the distribution area of deep BCS,the key values of foundation replacement depth for controlling the crack depth of the embankment with the height of 1 to 4 m are 1.2 and 1.5 m.In the low filling section,when the buried depth of BCS is 2,3 and 4 m,the key values of the foundation replacement depth to control the crack depth of the embankment are 0.8 and 1.2 m.In order to control the embankment cracking induced by the water losing shrinkage of BCS,a reasonable replacement depth of the foundation should be selected while slope protection is carried out well.
文摘Because there are plenty of clay particles in the flush fluid of Pingguo Aluminum Mine, the consolidationtechnology in geotechnical engineering was adopted to carry out the disassociation of water and soil disassociation. Inthis method, vacuum method, electro-osmosis and chemical flocculation were used comprehensively to separate soilfrom flush fluid. The experiments of the method of "vacuum + electro-osmosis" for drainage was made. After pretreat-ing the flush fluid, suction pressure was offered by the sand well in the bottom and electro-osmosis was used to drainoff water. The results of the experiment show that the good effect can be obtained in drainage when the electric gradi-ent is greater than 8.3 V/cm and the quantity of sand well is more than 6. In industrial production, it is necessary to in-crease the quantity of sand well, to arrange the electrodes rationally and to set up an intermittent electric circuit. On thebasis of the experiments , the industrial feasible flow was put forward. It may be a helpful attempt to apply consolida-tion technology to the fields of the environmental protection and so on.
