Therefore, the results are true in its assumption range only, and in many. Table 1 from extended mononobeokabe method for seismic. Translation of wall for active pressure comparison of theory with model test results computed by the proposed method show an excellent agreement with mononobeokabes method and are somewhat smaller than the those observed by sheriff et al6. Whitman 1970 or mononobeokabe methods overpredict the dynamic earth thrust. Cohesionless soil, mononobeokabe, earthquake, centrifuge 18. Worked example 1 design of cantilever pol retaining.
K instructions geogrid keywall appedix keystone r e t a i. The mononobeokabe mo method is based on coulombs theory of static soil pressures and was originally developed for gravity walls retaining cohesion less backfill materials. For the quay walls that are of interest here, in particular, the situation becomes far more. Home geotechnique list of issues volume 45, issue 1. In design procedure, the seismic coefficient method is widely employed, in which the earth pressure and inertia force are calculated by converting the seismic force into a static load. Mononobeokabe method mo, a seismic version of coulomb theory, was proposed based on pseudostatic earthquake loading for granular. Mononobeokabe method mo, a seismic version of coulomb theory, was proposed based on pseudostatic earthquake loading for granular soils. Okabe 1926 and mononobe and matsuo 1929, which is popularly known as mononobeokabe mo method, following the great kanto earthquake of 1923. Chapter14 a procedure for seismic design of retaining. Pressures and forces on the walls of a number of idealized wallsoil problems are analyzed. These studies were motivated by the fact that the current seismic design methodologies based on the work of mononobeokabe in the 1920s to predict very large dynamic forces in areas of high seismicity. Professor in charge of thesis on behalf of the advisory committee approved. However, there is no clear empirical basis for treating the seismic force as a static force, and recent experimental research has shown that.
Gravity retaining walls are widely used in japan because of their simplicity of structure and ease of construction. Mononobeokabe dynamic earth pressure coecient calculation. Jun 28, 2016 the mononobe okabe theory is used to evaluate the dynamic earth pressures. On seismic response of stiff and flexible retaining structures. The proposed solution is essentially an approximate yieldline approach, based on the theory of discontinuous stress. While various mo difications of this m ethod have been. It is a modification of coulombs classic earth pressure theory which takes into account the inertia forces on a potential sliding wedge caused by earthquake accelerations. Mononobe okabe equation is the modification of coulomb equation and it considers seismic forces. Extension of mononobeokabe theory to evaluate seismic active. Missouri university of science and technology scholars mine. Mononobe okabe theory continuum mechanics force scribd. Pdf extension of mononobeokabe theory to evaluate seismic. Prediction of seismic active earth pressure using curved.
There have been very few documented cases of waterfront anchored walls that have survived earthquakes or of walls that have failed for reasons other than liquefaction. Nov 29, 20 in the design procedure for a retaining wall, the pseudostatic method has been widely used and dynamic earth pressure is calculated by the mononobeokabe method, which is an extension of coulombs earth pressure theory computed by force equilibrium. Worked example 1 design of cantilever pol retaining walls. Commonly used mononobe okabe method considers pseudostatic approach, which gives the linear distribution of seismic earth pressure in an approximate way. A closedform stress plasticity solution is presented for gravitational and earthquakeinduced earth pressures on retaining walls. Design of cantilever pole retaining walls to resist earthquake loading for residential sites.
The study was motivated by the lack of suitable earthquake design data for relatively rigid structures on firm foundations in situations where the foundation, structure and retained soil remain essentially elastic. Earth pressure is usually calculated by the mononobeokabe formula, which applies coulombs earth pressure computed from the equilibrium of forces in the. Seismic lateral pressures for design of rigid walls. Chapter 14 a procedure for seismic design of retaining walls. Earth pressure is usually calculated by the mononobe okabe formula, which applies coulombs earth pressure computed from the equilibrium of forces in the static state. Scribd is the worlds largest social reading and publishing site. Considering some simple assumptions and using a closed form method, mo solves the equations of equilibrium and. Cy chin, queenstown use of mononobeokabe equations in seismic design of retaining walls in shallow soils c y chin urs new zealand ltd. Mononobe okabe theory free download as excel spreadsheet. Other researchers, however, found satisfactory agreement between mononobeokabe and measurements for dry sandy soil e. A great deal of research 718 have been performed since the advancement of the mononobe okabe theory referred hereafter as the mo method to evaluate its accuracy. The mononobeokabe solution treats earthquake loads as pseudodynamic, generated by uniform acceleration in the backfill.
Cohesionless soil, mononobe okabe, earthquake, centrifuge 18. However, the hyogokennambu earthquake of 1995 prompted the need to reexamine seismic design methods for various civil engineering structures. Pdf an alternative to the mononobeokabe equations for. Reexamination of mononobeokabe theory of gravity retaining. Coecient k is the ratio of lateral to vertical eective stress at the wallback. Use of mononobeokabe equations in seismic design of. Extended mononobeokabe method for seismic design of. Pdf an effort is made to evaluate the formulation of seismic active earth pressure behind a nonvertical retaining wall supporting c backfill. Worked example to accompany mbie guidance on the seismic design of retaining structures for residential sites in greater christchurch version 2 november 2014. The pioneering work in determining the static earth pressure was done by. Elle constitue une methode analytique, voire graphique pour certains cas particuliers. Journal of the japanese society of civil engineers, tokyo, japan 12 1. The mononobeokabe theory is used to evaluate the dynamic earth pressures. It was concluded that both the elastic theory and the mononobe okabe method have valid applications in the design of wall structures subjected to earthquake motions, but that because of significant differences in the solutions obtained from each method, care is required in selecting the most appropriate method for a particular situation.
Mononobeokabe mo method is still employed as the first option to estimate lateral earth pressures during earthquakes by geotechnical engineers. The mo method is a direct extension of the static coulomb theory to pseu. The classical equations of coulomb,, and mononobeokabe,,, are being widely used for determining earth pressures due to gravitational and earthquake loads, respectively. Okabe 1926 is commonly used to determine the magnitude and distribution of seismic pressure on a retaining wall. Pdf seismic earth pressures experiments and analyses. This theory is an extension of coulombs theory in which the effect of earthquake. The lateral earth pressure is important because it affects the consolidation behavior and strength of the soil and because it is considered in the design of geotechnical engineering structures such as retaining walls, basements, tunnels, deep foundations and braced excavations. Prev next modification of mononobeokabe theory authors. An alternative to the mononobeokabe equations for seismic. The effect of various parameters on dynamic active earth.
In such case, p a acts at a point located at h3 above the height of wall of height h. Pdf extended mononobeokabe method for seismic design. Considering some simple assumptions and using a closed form method, mo solves the equations of equilibrium and suggests seismic active and passive lateral earth pressures. Evaluation of unsaturated layer effect on seismic analysis. The theory currently used in the seismic design of retaining walls is represented by the mononobe okabe mo pseudo static approach okabe 6. Beside other complex theoretical models and numerical methods, mo. Extended mononobeokabe method for seismic design of retaining walls pdf download available pin 57916970 mononobe okabe theory trigonometric functions friction. Coulomb theory does not explicitly predict the distribution of active pressure, but it can be shown to be triangular for linear backfill surface with no loads.
The coefficient of lateral earth pressure, k, is defined as the ratio of the horizontal effective stress. Pdf extended mononobeokabe method for seismic design of. Use of mononobeokabe equations in seismic design of retaining walls in shallow soils proc. The conventional mononobeokabe method is widely used in practice, but is only applicable for calculating total seismic earth pressure of cohesionless soil, not for solving earth pressure distribution. Positive values correspond to backfill surface inclining upwards away from the wall. Mononobe okabe mo method is still employed as the first option to estimate lateral earth pressures during earthquakes by geotechnical engineers. Earth pressure is usually calculated by the mononobeokabe formula, which applies coulombs earth pressure computed from the equilibrium of forces in the static state. A great deal of research 718 have been performed since the advancement of the mononobeokabe theory referred hereafter as the mo method to evaluate its accuracy. Security classification of this report unclassified 20. Beles et voinea, 1958 au cas dun sol avec cohesion. The theory currently used in the seismic design of retaining walls is represented by the mononobeokabe mo pseudo static approach okabe 6. In this paper, the pseudodynamic method is used to compute the distribution of seismic. For the maximum passive conditions in cohesionless backfill fig.
The earthquakeinduced pressures on soilretaining structures are investigated. Mononobeokabe extended the theory including earthquake loads. Initially okabe 1 and mononobe and matsuo had proposed the theory to compute 2 how to cite this paper. Earthquakeinduced soil pressures on structures caltechauthors. Cy chin, queenstown use of mononobe okabe equations in seismic design of retaining walls in shallow soils c y chin urs new zealand ltd. The mo theory assumes that the backfill behind the wall is cohesionless soil and the slip surface is a plane, and the theory cannot obtain the. The method was a modified version of coulomb theory in. The latter formula used to compute lateral earth pressure acts on retaining walls but it cannot be employed to calculate internal force which backfill soil impacts on the retaining walls during earthquake. This theory is an extension of coulombs theory in which the effect of earthquakeinduced inertia forces arising in the soil due to. Use of mononobe okabe equations in seismic design of retaining walls in shallow soils proc. Prev next modification of mononobe okabe theory authors. Mononobe n, matsuo h 1929, on the determination of earth pressure during earthquakes.
A comparison of the stiffness of the chalk at mundford from a seismic survey and a large scale tank test. Calculation of mononobeokabe earth pressure coefficient. Extension of mononobeokabe approach to unstable slopes by sara ebrahimi approved. Pseudodynamic approach of seismic active earth pressure. Research article extended mononobeokabe method for seismic. This document is available to the public through the national technical information service, springfield, va 22161 19.
Knowledge of seismic active earth pressure behind rigid retaining wall is very important in the design of retaining wall in earthquake prone region. In this paper, the pseudodynamic method is used to compute the distribution of. Commonly used mononobeokabe method considers pseudostatic approach, which gives the linear distribution of seismic earth pressure in an approximate way. Seismic lateral pressures on retaining walls earth. The effective stress is the intergranular stress calculated by subtracting the pore pressure from the total stress as described in soil mechanics. Design of earth retaining structures for dynamic loads, prof h. In the design procedure for a retaining wall, the pseudostatic method has been widely used and dynamic earth pressure is calculated by the mononobeokabe method, which is an extension of coulombs earth pressure theory computed by force equilibrium. Research article extended mononobeokabe method for. Mononobe okabe method mo, a seismic version of coulomb theory, was proposed based on pseudostatic earthquake loading for granular soils. Mononobe and matsuo, and okabe mo proposed a method to determine lateral earth pressure of granular cohesionless soils during earthquake. Insight into seismic earth and water pressures against. Mononobeokabe equation is the modification of coulomb equation and it considers seismic forces. Canadian geotechnical journal canadian science publishing. The mononobe okabe method mononobe and matsuo 1929.
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