scholarly journals A SEMI-ANALYTICAL SOLUTION FOR CONSOLIDATION AROUND A SPHERICAL CAVITY IN AN ELASTO-PLASTIC MEDIUM AND ITS POTENTIAL APPLICATION FOR TUNNELING

2014 ◽  
Vol 11 (02) ◽  
pp. 1342010 ◽  
Author(s):  
A. S. OSMAN ◽  
M. ROUAINIA
Keyword(s):  
Analytical Solution ◽  
Pore Water ◽  
Spherical Cavity ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Plastic Behavior ◽  
Element Analysis ◽  
Perfectly Plastic ◽  
Elastic Perfectly Plastic ◽  
Contraction Theory

An analytical solution for consolidation around spherical cavity contraction is developed. This solution has the potential to evaluate consolidation around tunnel heads. The initial excess pore water pressure immediately after the creation of the cavity is estimated from the cavity expansion/contraction theory using a linear-elastic-perfectly-plastic soil model. Expressions for the decay of pore water pressure with time are obtained using elasticity. Curves showing the variation of pore water pressure with time are plotted in nondimensional form. Comparison with two-dimensional coupled stress-pore pressure finite element analysis shows that the proposed semi-analytical solution can successfully predict the poro-elasto-plastic behavior around spherical cavity.

scholarly journals Analysis of shallow failures triggered by the 14-16 November 2002 event in the Albaredo valley, Valtellina (Northern Italy)

2005 ◽  
Vol 2 ◽  
pp. 305-308 ◽  
Author(s):  
S. Dapporto ◽  
P. Aleotti ◽  
N. Casagli ◽  
G. Polloni
Keyword(s):  
Pore Water ◽  
Slope Failure ◽  
Pore Water Pressure ◽  
Limit Equilibrium ◽  
Water Pressure ◽  
Coupled Analysis ◽  
Element Analysis ◽  
Seepage Analysis ◽  
The North ◽  
Pressure Distributions

Abstract. On 14-16 November 2002 the North Italy was affected by an intense rainfall event: in the Albaredo valley (Valtellina) more than 200 mm of rain fell triggering about 50 shallow landslides, mainly soil slips and soil slip-debris flows. Landslides occurred above the critical rainfall thresholds computed by Cancelli and Nova (1985) and Ceriani et al. (1994) for the Italian Central Alps: in fact the cumulative precipitation at the soil slips initiation time was 230 mm (in two days) with a peak intensity of 15 mm/h. A coupled analysis of seepage and instability mechanisms is performed in order to evaluate the potential for slope failure during the event. Changes in positive and negative pore water pressures during the event are modelled by a finite element analysis of water flow in transient conditions, using as boundary condition for the nodes along the slope surface the recorded rainfall rate. The slope stability analysis is conducted applying the limit equilibrium method, using pore water pressure distributions obtained in the different time steps by the seepage analysis as input data for the calculation of the factor of safety.

The Finite-Element Analysis of Characteristics of Soil Slope Seepage Field Change in Rainstorm Condition

2012 ◽  
Vol 204-208 ◽  
pp. 50-53
Author(s):  
Zhong Ming He ◽  
Wei Wu ◽  
Ling Zeng ◽  
Zhong Xin Cai
Keyword(s):  
Finite Element ◽  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Element Analysis ◽  
Finite Element Software ◽  
The Finite Element Analysis ◽  
Pressure Region ◽  
Pressure Area ◽  
Depth Of Infiltration

A numerical model was built by Finite Element software,discussed the effect of rainfall on slope pore water pressure、volatile water content and depth of infiltration in rainstorm condition. The results indicated that: (1)the variation of slope surface pore water pressure is more significant and the depth of infiltration is larger with the increase of rainfall intensity on the condition of fixed rainfall duration;(2)The slope section appears three pore water pressure divisions: transient saturated zone、negative pressure region and hydrostatic pressure area after the rainfall.

The Finite-Element Analysis of Characteristics of Soil Slopeseepage Field Change in Continuous Rain Condition

2012 ◽  
Vol 238 ◽  
pp. 451-454
Author(s):  
Zhong Ming He ◽  
Wei Wu ◽  
Ling Zeng ◽  
Zhong Xin Cai
Keyword(s):  
Finite Element ◽  
Ground Water ◽  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Element Analysis ◽  
Finite Element Software ◽  
The Finite Element Analysis ◽  
Pressure Area ◽  
Depth Of Infiltration

A numerical model is built by Finite Element Software, discussed the effect of rainfall on slope pore water pressure, volatile water content and depth of infiltration in continuous rain condition. The result indicated that when the rainfall intensity and rainfall duration reach a certain condition, the ground water table rises slowly, and mostly, the spill points of ground water locate in the foot of slope. The slope section appears three pore water pressure divisions: transient saturated zone, negative pressure region and hydrostatic pressure area after the rain.

Local Analytical Solution of One Dimension Consolidation Equation

2011 ◽  
Vol 243-249 ◽  
pp. 3113-3116
Author(s):  
Bo Feng ◽  
Run Tao Zhan ◽  
Feng Zhou
Keyword(s):  
Differential Equation ◽  
Analytical Solution ◽  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Simple Relation ◽  
Solution Procedure ◽  
Rate Of Change ◽  
One Dimension ◽  
Fractional Differential

One dimension consolidation equation can be transformed into a fractional differential equation by Laplace transform. The transformed equation can leads to a simple relation between pore water pressure and its time revolution. When local rate of change of the pore water pressure is determined, the local pore water pressure can be obtained without having to solve the consolidation equation within the entire domain. The simplicity of the solution procedure is highlighted considering by a example..

scholarly journals An Analytical Solution of Flow and Progressive Wave-Induced Residual Pore Water Pressure in Seabed

2015 ◽  
Vol 31 (7) ◽  
pp. 13-28
Author(s):  
Kwang-Ho Lee ◽  
Dong-Wook Kim ◽  
Gi-Chun Kang ◽  
Do-Sam Kim ◽  
Tae-Hyung Kim
Keyword(s):  
Analytical Solution ◽  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Progressive Wave ◽  
Wave Induced

scholarly journals Analytical Solution for One-Dimensional Consolidation of Soil with Exponentially Time-Growing Drainage Boundary under a Ramp Load

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Ming Sun ◽  
Meng-fan Zong ◽  
Shao-jun Ma ◽  
Wen-bing Wu ◽  
Rong-zhu Liang
Keyword(s):  
Analytical Solution ◽  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Excess Pore Water Pressure ◽  
One Dimensional ◽  
The One ◽  
Interface Parameters ◽  
Ramp Load ◽  
Excess Pore

By introducing the exponentially time-growing drainage boundary, this paper investigated the one-dimensional consolidation problem of soil under a ramp load. Firstly, the one-dimensional consolidation equations of soil are established when there is a ramp load acting on the soil surface. Then, the analytical solution of excess pore water pressure and consolidation degree is derived by means of the method of separation of variables and the integral transform technique. The rationality of this solution is also verified by comparing it with other existing analytical solutions. Finally, the consolidation behavior of soil is studied in detail for different interface parameters or loading scheme. The results show that the exponentially time-growing drainage boundary can reflect the phenomenon that the excess pore water pressure at the drainage boundaries dissipates smoothly rather than abruptly from its initial value to the value of zero. By adjusting the values of interface parameters b and c, the presented solution can be degraded to Schiffman’s solution, which can compensate for the shortcoming that Terzaghi’s drainage boundary can only consider the two extreme cases of fully pervious and impervious boundaries. The significant advantage of the exponentially time-growing drainage boundary is that it can be applied to describe the asymmetric drainage characteristics of the top and bottom drainage surfaces of the actual soil layer by choosing the appropriate interface parameters b and c.

scholarly journals Analytical solution for one-dimensional consolidation of double-layered soil with exponentially time-growing drainage boundary

2018 ◽  
Vol 14 (10) ◽  
pp. 155014771880671 ◽  
Author(s):  
Wenbing Wu ◽  
Mengfan Zong ◽  
M Hesham El Naggar ◽  
Guoxiong Mei ◽  
Rongzhu Liang
Keyword(s):  
Analytical Solution ◽  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Soil Layer ◽  
Excess Pore Water Pressure ◽  
One Dimensional ◽  
Present Solution ◽  
The One ◽  
Excess Pore

In this article, the exponentially time-growing drainage boundary is introduced to study the one-dimensional consolidation problem of double-layered soil. First, the one-dimensional consolidation equations of soil underlying a time-dependent loading are established. Then, the analytical solution of excess pore water pressure and average consolidation degree is obtained by utilizing the method of separation of variables when the soil layer is separately undergone instantaneous load and single-stage load. The validity of the present solution is proven by the comparison with other existing analytical solution. Finally, the influence of soil properties and loading scheme on the consolidation behavior of soil is investigated in detail. The results indicate that, the present solution can be degraded to Xie’s solution utilizing Terzaghi’s drainage boundary by adjusting the interface parameter, that is to say, Xie’s solution can be regarded as a special case of the present solution. The interface parameter has a significant influence on the excess pore water pressure of soil, and the larger interface parameter means the better drainage capacity of the soil layer.

A Semi-Analytical Solution for the Sliding Inception of a Spherical Contact

2003 ◽  
Vol 125 (3) ◽  
pp. 499-506 ◽  
Author(s):  
Lior Kogut ◽  
Izhak Etsion
Keyword(s):  
Friction Coefficient ◽  
Analytical Solution ◽  
Failure Modes ◽  
Static Friction ◽  
Element Analysis ◽  
Tangential Load ◽  
Spherical Contact ◽  
Elastic Plastic ◽  
Perfectly Plastic ◽  
Elastic Perfectly Plastic

A finite element analysis, for an elastic perfectly plastic sphere normally loaded by a rigid flat, is combined with an approximate analytical solution to evaluate the maximum tangential load (static friction) that can be supported by the spherical contact at the inception of sliding. Sliding inception is treated as a failure mechanism based on plastic yield rather than a Coulomb friction law with a certain friction coefficient. Two different failure modes are identified, either on the contact area or below it, depending on the elastic-plastic status of the normal preloading. A limiting normal preload is found above which the contact cannot support any additional tangential load. Simple analytical expressions for an “internal static friction coefficient” are presented for both the elastic and the elastic-plastic regimes.

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