On seismic response of stiff and flexible retaining structures. Research article extended mononobeokabe method for. Under the previous version of the building code walls were designed for a pga0. Calculation of mononobeokabe earth pressure coefficient. The general features of behavior are illustrated by field experiences, results from laboratory model tests and from theoretical. Considering some simple assumptions and using a closed form method, mo solves the equations of equilibrium and. The classical equations of coulomb 14,10 and this expectation does not seem to diminish by the advent mononobe okabe 511. A series of dynamic numerical analyses is being conducted to. Pdfdateien in einzelne seiten aufteilen, seiten loschen oder drehen, pdfdateien einfach zusammenfugen oder.
The mononobe okabe mo method is a pseudostatic approach, which incorporates seismic accelerations in the form of inertial forces into coulombs 1776 limit. Seismic design of retaining structures gravity walls october 2009 part a. Seismic lateral pressures for design of rigid walls. Mononobe n, matsuo h 1929, on the determination of earth pressure during earthquakes. Coulombs solution to seismic passive earth pressure on. Pseudostatic limit analysis by discontinuity layout. 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. Extended mononobeokabe method for seismic design of. The report discusses the seismic design of gravity walls retaining granular backfill without pore water. Dieses kostenlose tool erlaubt es mehrere pdfs oder bilddateien miteinander zu einem pdfdokument zu verbinden. A comparison of the stiffness of the chalk at mundford from a seismic survey and a large scale tank test.
The current state of practice for the seismic design of basement walls in vancouver is based on the mononobe okabe mo method using a peak ground acceleration pga of 0. 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. Insight into seismic earth and water pressures against. The mo method is a direct extension of the static coulomb theory to pseu. For this case mononobeokabe method reduces to coulomb theory.
Pdf zusammenfugen online pdf dateien zusammenfugen. Knowledge of seismic active earth pressure behind rigid retaining wall is very important in the design of retaining wall in earthquake prone region. 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. Seismic lateral pressures on retaining walls earth. It was concluded that both the elastic theory and the mononobe okabe method have valid applications in the. In this paper, the pseudodynamic method is used to compute the distribution of. 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. Mononobe okabe s theory have been included in numerous codes of seismic design.
Seismic earth pressure coefficient civil engineering community usually, vertical acceleration, wall friction angle and wall inclination are the above equations can be simplified as. Coulomb 1776 first studied the problem of lateral earth pressures on retaining structures. Journal of the japanese society of civil engineers, tokyo, japan 12 1. The mononobe okabe theory is used to evaluate the dynamic earth pressures. Initially okabe 1 and mononobe and matsuo had proposed the theory to compute 2 how to cite this paper. Seismic earth pressure development in sheet pile retaining walls. 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. Pdf extended mononobeokabe method for seismic design. Insight into seismic earth and water pressures against caisson quay walls p. Seismic assessment of basement walls for different design.
Ice virtual library essential engineering knowledge. 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. It is clear that a revision of these recommendations must be done. Pdf an alternative to the mononobeokabe equations for. Seismic lateral pressures on retaining walls indepth structural 8 nov 10 17. Mononobeokabe mo method is still employed as the rst option to estimate lateral earth pressures during earthquakes by geotechnical engineers.
English users manual help is available for this software in both chm and pdf. Translation of wall for active pressure comparison of theory with model test results computed by the proposed method show an excellent. The mononobe okabe method mononobe and matsuo 1929. Pseudodynamic approach of seismic active earth pressure. Mononobeokabe mo method is still employed as the first option to estimate lateral earth pressures during earthquakes by geotechnical engineers. Worked example 4 design of a tiedback retaining wall to. Commonly used mononobe okabe method considers pseudostatic approach, which gives the linear distribution of seismic earth pressure in an approximate way. Worked example 1 design of cantilever pol retaining. He used limit equilibrium theory, which considers the failing soil block as a free body in order to determine the limiting horizontal earth pressure.
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. Missouri university of science and technology scholars mine. 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. Evaluation of unsaturated layer effect on seismic analysis. Consequently, recommendation is made for the use of reduced values based on the seed. The result obtained from mononobe okabe theory and from the present study are also shown in fig. Okabe 1926 and mononobe and matsuo 1929, which is popularly known as mononobe okabe mo method, following the great kanto earthquake of 1923. The computation of each static and dynamic pressure acting on retaining wall need more research and site selection is becoming codified. A series of dynamic numerical analyses are conducted to study the seismic performance of basement walls designed for the mo earth pressures derived from.
Chapter 14 a procedure for seismic design of retaining walls. 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 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. Okabe 1926 is commonly used to determine the magnitude and distribution of seismic pressure on a retaining wall. 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. This method has generally been used for cohesionless soils only. Mononobe okabe mo method is still employed as the first option to estimate lateral earth pressures during earthquakes by geotechnical engineers. Static and dynamic active earth pressure springerlink. Our pdf merger allows you to quickly combine multiple pdf files into one single pdf document, in just a few clicks. Gravity retaining walls are widely used in japan because of their simplicity of structure and ease of construction.
However, the hyogokennambu earthquake of 1995 prompted the need to reexamine seismic design methods for various civil engineering structures. With pdf merger you can merge your multiple pdf files to a single pdf file in matter of seconds. 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. 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. 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. Equation cited in seed and whitman 1970 is incorrect. Table 1 from extended mononobeokabe method for seismic. A general solution for the determination of total i. Their analyses have provided a popular solution to the problem of cohesionless soils. This equation for k pe is much less used in practice than k ae where. 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. While the original mo solution did not account for cohesion, several authors have extended the mo solution to account for c. 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.