ABSTRACT: In 1997 and 1998 an original special experimental equipment was designed and developed including bicomponent tensors, a large stand and others. The retaining wall of the stand is measured and can be arbitrarily moved. In 1998 and the first half 1999 was made the first medium-term experiment with a mass of very dry flowing sand. was made which has brought some unexpected and new results. The paper presents information about the research and the experiment and shows the origin of slip surfaces due to three types of movements of the retaining wall. Finally, the paper presents measured pressures. INTRODUCTION No satisfactory procedures for the computation of dynamic earth pressures are known and the knowledge used for the computation of static earth pressures does not correspond with the significance of the problem, either. Its complicated character and the state of the solution of earth (lateral) pressures is testified to also by the fact that the valid preliminary issue of EUROCODE 7–1 (1994) defines formulae for the active pressure at rest (J.ky 1944) and neglects the passive pressure at rest (Pru_ka 1973). An advanced numerical model based on a comprehensive nonlinear dependence, has shown that the Code limit movements {Art.8.5.4/2} do not correspond with mobilization of the peak shear strength (Koudelka 1996, 1998a, 1999b). Then the Code presents (Annex G) the sample procedure to determine the extreme (peak) values of earth pressures for the case of peak shear strength mobilization. It gives the coefficients K for the effect of material weight in 9 diagrams depending on frictional and geometrical parameters. The special numerical model of earth pressures on curved slip surfaces is presented in the paper no. 0553. The paper no. 0565 sums the present results in drafting of a more general theory of earth pressures.

ABSTRACT: The contemporary conventional theory of earth pressure is based on the very old simple idea of a single shear or slip soil mass surface defining earth pressure stress along the whole height of the retaining structure. More over, the conventional theory neglects any influence of the mass shear strength decrease on earth pressure due to the over-mobilization, when the strength decreases to its residual value and, also does not consider any other value of pressure at rest except of the value of active pressure at rest. After a number of wide analyses the Paper designs a non-conventional conception of the lateral pressure theory on the advanced comprehensive non-linear dependence based. This theory takes into account both the singularity of pressure at rest and the shear strength decrease from the peak value to the residual one. INTRODUCTION The actual theory of the earth pressure (in mechanics more widely as "lateral pressure") is based particularly on the works of Ohde, Terzaghi, Caquot-Kerisel, Ehrenberg, Jáky, de Wett, Sowada, Siedek, Myslivec, Pruška, Janbu, Brooker-Ireland, Morgenstern, Eisenstein, Gudehus {1980} and others for static problems, while Tanaka, Finagenov, Alampalli, Lemos, Byrne, Crespellani, Simic and others should be mentioned in connection with dynamic problems. This was confirmed by the results of the last special IS Tokyo 1999 "Geotechnical Aspects of Underground Construction in Soft Ground" {Ariizumi et al., Day, Kort et al., Onishi&Sugawara, Powderham, Siemer et al., Uchiyama and others}. The reason is probably the complex nonlinear dependence of the lateral pressure on the movement of structure neary the rest area with a history similar to the singularity (Koudelka 1990). The recently published model solves the computation of active and passive lateral pressure on curved (circular) shear surfaces by an original Apriori Integration Method {AIM} {Koudelka 1997, Koudelka&Fischer 1999}.