The effect of various parameters on dynamic active earth. 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. Prev next modification of mononobe okabe theory authors. Chapter 14 a procedure for seismic design of retaining walls. For the quay walls that are of interest here, in particular, the situation becomes far more. 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. Extended mononobeokabe method for seismic design of retaining walls pdf download available pin 57916970 mononobe okabe theory trigonometric functions friction. Mononobe okabe mo method is still employed as the first option to estimate lateral earth pressures during earthquakes by geotechnical engineers. Pdf an alternative to the mononobeokabe equations for.
Beside other complex theoretical models and numerical methods, mo. Jun 28, 2016 the mononobe okabe theory is used to evaluate the dynamic earth pressures. Insight into seismic earth and water pressures against. Commonly used mononobe okabe method considers pseudostatic approach, which gives the linear distribution of seismic earth pressure in an approximate way.
Beles et voinea, 1958 au cas dun sol avec cohesion. Worked example 1 design of cantilever pol retaining walls. The mononobe okabe method mononobe and matsuo 1929. Home geotechnique list of issues volume 45, issue 1. 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. Pdf extended mononobeokabe method for seismic design of. Positive values correspond to backfill surface inclining upwards away from the wall.
This theory is an extension of coulombs theory in which the effect of earthquake. Seismic lateral pressures for design of rigid walls. Mononobe okabe method mo, a seismic version of coulomb theory, was proposed based on pseudostatic earthquake loading for granular soils. Whitman 1970 or mononobeokabe methods overpredict the dynamic earth thrust. The classical equations of coulomb,, and mononobeokabe,,, are being widely used for determining earth pressures due to gravitational and earthquake loads, respectively. Calculation of mononobeokabe earth pressure coefficient.
Use of mononobeokabe equations in seismic design of. 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. A comparison of the stiffness of the chalk at mundford from a seismic survey and a large scale tank test. The mo method is a direct extension of the static coulomb theory to pseu. Use of mononobeokabe equations in seismic design of retaining walls in shallow soils proc. In this paper, the pseudodynamic method is used to compute the distribution of. Cy chin, queenstown use of mononobe okabe equations in seismic design of retaining walls in shallow soils c y chin urs new zealand ltd.
Scribd is the worlds largest social reading and publishing site. Mononobe okabe theory continuum mechanics force scribd. The earthquakeinduced pressures on soilretaining structures are investigated. Mononobeokabe dynamic earth pressure coecient calculation.
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. Commonly used mononobeokabe method considers pseudostatic approach, which gives the linear distribution of seismic earth pressure in an approximate way. Pseudodynamic approach of seismic active earth pressure. 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. 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. An alternative to the mononobeokabe equations for seismic. The mononobeokabe theory is used to evaluate the dynamic earth pressures. Use of mononobe okabe equations in seismic design of retaining walls in shallow soils proc. Initially okabe 1 and mononobe and matsuo had proposed the theory to compute 2 how to cite this paper. Extension of mononobeokabe theory to evaluate seismic active. Therefore, the results are true in its assumption range only, and in many. On seismic response of stiff and flexible retaining structures.
This document is available to the public through the national technical information service, springfield, va 22161 19. Mononobeokabe equation is the modification of coulomb equation and it considers seismic forces. In such case, p a acts at a point located at h3 above the height of wall of height h. Earth pressure is usually calculated by the mononobeokabe formula, which applies coulombs earth pressure computed from the equilibrium of forces in the. Research article extended mononobeokabe method for. Chapter14 a procedure for seismic design of retaining. The method was a modified version of coulomb theory in. Other researchers, however, found satisfactory agreement between mononobeokabe and measurements for dry sandy soil e. Elle constitue une methode analytique, voire graphique pour certains cas particuliers. Worked example to accompany mbie guidance on the seismic design of retaining structures for residential sites in greater christchurch version 2 november 2014. Evaluation of unsaturated layer effect on seismic analysis.
Design of earth retaining structures for dynamic loads, prof h. Mononobe n, matsuo h 1929, on the determination of earth pressure during earthquakes. Earthquakeinduced soil pressures on structures caltechauthors. 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.
Design of cantilever pole retaining walls to resist earthquake loading for residential sites. The theory currently used in the seismic design of retaining walls is represented by the mononobeokabe mo pseudo static approach okabe 6. Cohesionless soil, mononobe okabe, earthquake, centrifuge 18. This theory is an extension of coulombs theory in which the effect of earthquakeinduced inertia forces arising in the soil due to. 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. The proposed solution is essentially an approximate yieldline approach, based on the theory of discontinuous stress. Research article extended mononobeokabe method for seismic. Missouri university of science and technology scholars mine.
Mononobe and matsuo, and okabe mo proposed a method to determine lateral earth pressure of granular cohesionless soils during earthquake. Extension of mononobeokabe approach to unstable slopes by sara ebrahimi approved. 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. Mononobe okabe theory free download as excel spreadsheet. In this paper, the pseudodynamic method is used to compute the distribution of seismic. 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. Prediction of seismic active earth pressure using curved. Pressures and forces on the walls of a number of idealized wallsoil problems are analyzed. The coefficient of lateral earth pressure, k, is defined as the ratio of the horizontal effective stress. A closedform stress plasticity solution is presented for gravitational and earthquakeinduced earth pressures on retaining walls. Reexamination of mononobeokabe theory of gravity retaining. Security classification of this report unclassified 20.
Professor in charge of thesis on behalf of the advisory committee approved. 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. 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. Seismic lateral pressures on retaining walls earth. 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. 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. For the maximum passive conditions in cohesionless backfill fig. Worked example 1 design of cantilever pol retaining.
Okabe 1926 and mononobe and matsuo 1929, which is popularly known as mononobeokabe mo method, following the great kanto earthquake of 1923. Mononobeokabe mo method is still employed as the first option to estimate lateral earth pressures during earthquakes by geotechnical engineers. K instructions geogrid keywall appedix keystone r e t a i. Cohesionless soil, mononobeokabe, earthquake, centrifuge 18. Knowledge of seismic active earth pressure behind rigid retaining wall is very important in the design of retaining wall in earthquake prone region. 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. 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. Mononobeokabe method mo, a seismic version of coulomb theory, was proposed based on pseudostatic earthquake loading for granular. 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.
Pdf extension of mononobeokabe theory to evaluate seismic. Gravity retaining walls are widely used in japan because of their simplicity of structure and ease of construction. Okabe 1926 is commonly used to determine the magnitude and distribution of seismic pressure on a retaining wall. Mononobeokabe method mo, a seismic version of coulomb theory, was proposed based on pseudostatic earthquake loading for granular soils. Prev next modification of mononobeokabe theory authors. Considering some simple assumptions and using a closed form method, mo solves the equations of equilibrium and. The effective stress is the intergranular stress calculated by subtracting the pore pressure from the total stress as described in soil mechanics.
Mononobe okabe equation is the modification of coulomb equation and it considers seismic forces. Pdf an effort is made to evaluate the formulation of seismic active earth pressure behind a nonvertical retaining wall supporting c backfill. Pdf extended mononobeokabe method for seismic design. Coecient k is the ratio of lateral to vertical eective stress at the wallback. Journal of the japanese society of civil engineers, tokyo, japan 12 1. Extended mononobeokabe method for seismic design of. However, there is no clear empirical basis for treating the seismic force as a static force, and recent experimental research has shown that. While various mo difications of this m ethod have been. Mononobeokabe extended the theory including earthquake loads. Pdf seismic earth pressures experiments and analyses. However, the hyogokennambu earthquake of 1995 prompted the need to reexamine seismic design methods for various civil engineering structures. Earth pressure is usually calculated by the mononobeokabe formula, which applies coulombs earth pressure computed from the equilibrium of forces in the static state. The theory currently used in the seismic design of retaining walls is represented by the mononobe okabe mo pseudo static approach okabe 6.
The pioneering work in determining the static earth pressure was done by. Cy chin, queenstown use of mononobeokabe equations in seismic design of retaining walls in shallow soils c y chin urs new zealand ltd. Table 1 from extended mononobeokabe method for seismic. 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. The mononobeokabe solution treats earthquake loads as pseudodynamic, generated by uniform acceleration in the backfill.
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