Evaluation of unsaturated layer effect on seismic analysis. Current state of practice for design of basement walls in vancouver is based on mononobe okabe mo theory using a code based peak ground acceleration pga0. 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. The computation of each static and dynamic pressure acting on retaining wall need more research and site selection is becoming codified. Okabe 1926 is commonly used to determine the magnitude and distribution of seismic pressure on a retaining wall. This equation for k pe is much less used in practice than k ae where. Research article extended mononobeokabe method for. For this case mononobeokabe method reduces to coulomb theory. The result obtained from mononobe okabe theory and from the present study are also shown in fig. Static and dynamic active earth pressure springerlink. While the original mo solution did not account for cohesion, several authors have extended the mo solution to account for c. The mononobe okabe mo method is based on coulombs theory of static soil pressures and was originally developed for gravity walls retaining cohesion less backfill materials. 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. Mononobe okabe s theory have been included in numerous codes of seismic design.
Pseudodynamic approach of seismic active earth pressure. The mononobe okabe method mononobe and matsuo 1929. A series of dynamic numerical analyses is being conducted to. Equation cited in seed and whitman 1970 is incorrect. 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. Kramer 1996 has summarised the limited research available on the performance of tiedback walls during earthquakes. Ice virtual library essential engineering knowledge. Consequently, recommendation is made for the use of reduced values based on the seed. Mononobeokabe mo method is still employed as the rst option to estimate lateral earth pressures during earthquakes by geotechnical engineers.
Pdf an alternative to the mononobeokabe equations for. With pdf merger you can merge your multiple pdf files to a single pdf file in matter of seconds. Pdf zusammenfugen pdfdateien online kostenlos zu kombinieren. Pdf extended mononobeokabe method for seismic design. Pdf seismic earth pressure development in sheet pile.
A general solution for the determination of total i. The conventional mononobe okabe 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. A series of dynamic numerical analyses are conducted to study the seismic performance of basement walls designed for the mo earth pressures derived from. Lateralk is a simple geotechnical software for calculating lateral earth pressure coefficients and forces behind retaining walls in static and earthquake condition based on rankine culomb formulas and also mononobe okabe methods. The mononobe okabe mo method is a pseudostatic approach, which incorporates seismic accelerations in the form of inertial forces into coulombs 1776 limit equilibrium analysis heyman, 1997. Their analyses have provided a popular solution to the problem of cohesionless soils.
The mononobe okabe theory is used to evaluate the dynamic earth pressures. This method has generally been used for cohesionless soils only. In this paper, the pseudodynamic method is used to compute the distribution of. Seismic lateral pressures for design of rigid walls. Gravity retaining walls are widely used in japan because of their simplicity of structure and ease of construction. It is clear that a revision of these recommendations must be done. Pdf zusammenfugen online pdf dateien zusammenfugen. The classical equations of coulomb 14,10 and this expectation does not seem to diminish by the advent mononobe okabe 511.
The static earth pressure coefficient for active states ka can be calculated according to the previous methodology if the seismic coefficients kh and kv are both set equal to zero, which means that the auxiliary angle is. Dieses kostenlose tool erlaubt es mehrere pdfs oder bilddateien miteinander zu einem pdfdokument zu verbinden. The mononobe okabe equation the mononobe and matsua 1929 and okabe 1926 analysis for dynamic lateral pressures is an extension of the coulomb sliding wedge theory to account for inertia forces corresponding to horizontal and vertical accelerations, k hg and k vg, acting on the sliding soil wedge behind the wall. Under the previous version of the building code walls were designed for a pga0. These studies were motivated by the fact that the current seismic design methodologies based on the work of mononobe okabe in the 1920s to predict very large dynamic forces in areas of high seismicity.
Seismic lateral pressures on retaining walls earth. Missouri university of science and technology scholars mine. Coulombs theory was generalized for cohesionless soils by muellerbreslau 3 to account for the frictional interaction between the retained soil and the wall face expressed by the angle. Worked example 4 design of a tiedback retaining wall to. Worked example 1 design of cantilever pol retaining. Seismic assessment of basement walls for different design. The mononobe okabe mo method is a pseudostatic approach, which incorporates seismic accelerations in the form of inertial forces into coulombs 1776 limit. The dynamic active earth pressure on retaining structures due to seismic loading is commonly obtained by using the modified coulombs approach which is known as the mononobe okabe method. Seismic design of retaining structures gravity walls october 2009 part a. Translation of wall for active pressure comparison of theory with model test results computed by the proposed method show an excellent.
The mo method is a direct extension of the static coulomb theory to pseu. Seismic earth pressure development in sheet pile retaining walls. Considering some simple assumptions and using a closed form method, mo solves the equations of equilibrium and. He used limit equilibrium theory, which considers the failing soil block as a free body in order to determine the limiting horizontal earth pressure. Journal of the japanese society of civil engineers, tokyo, japan 12 1. Our pdf merger allows you to quickly combine multiple pdf files into one single pdf document, in just a few clicks. On seismic response of stiff and flexible retaining structures. Okabe 1926 and mononobe and matsuo 1929, which is popularly known as mononobe okabe mo method, following the great kanto earthquake of 1923. English users manual help is available for this software in both chm and pdf. Coulomb 1776 first studied the problem of lateral earth pressures on retaining structures. Extended mononobeokabe method for seismic design of.
Insight into seismic earth and water pressures against. Chapter 14 a procedure for seismic design of retaining walls. Pdfdateien in einzelne seiten aufteilen, seiten loschen oder drehen, pdfdateien einfach zusammenfugen oder. Insight into seismic earth and water pressures against caisson quay walls p. Mononobe n, matsuo h 1929, on the determination of earth pressure during earthquakes. Knowledge of seismic active earth pressure behind rigid retaining wall is very important in the design of retaining wall in earthquake prone region. Seismic lateral pressures on retaining walls indepth structural 8 nov 10 17. Commonly used mononobe okabe method considers pseudostatic approach, which gives the linear distribution of seismic earth pressure in an approximate way. Seismic earth pressure coefficient civil engineering community usually, vertical acceleration, wall friction angle and wall inclination are the above equations can be simplified as.
However, the hyogokennambu earthquake of 1995 prompted the need to reexamine seismic design methods for various civil engineering structures. Seismic design of retaining wall is considerably complicated problem in which assumptions have to be considered in order to make indeterminable issue solvable employing theory of statics and differential calculus. Mononobeokabe mo method is still employed as the first option to estimate lateral earth pressures during earthquakes by geotechnical engineers. The report discusses the seismic design of gravity walls retaining granular backfill without pore water. Pseudostatic limit analysis by discontinuity layout. Gazetas motivated by the need to explain the large displacement and rotation that numerous caissontype quay walls suffered in the port of kobe during the devastating 1995 earthquake, a detailed numerical analysis is presented for. Because anchored walls are flexible and because it is difficult to prevent some perma nent displacement during a major seismic event, it is appro priate to use active and passive earth pressure theories to evaluate dynamic as well as static earth pressures. Mononobe okabe mo method is still employed as the first option to estimate lateral earth pressures during earthquakes by geotechnical engineers. It was concluded that both the elastic theory and the mononobe okabe method have valid applications in the. 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. The general features of behavior are illustrated by field experiences, results from laboratory model tests and from theoretical.
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