Méthode des coefficients de réaction appliquée en France pour les calculs des soutènements : influence de la variation des paramètres

Abstract

Methods based on subgrade reaction coefficients used in France to design retaining walls : parameter study AbstractWe recall herein the simple analogy between the behaviour of a perfectly elastic spring (Winkler model) and a « pseudo-elastic » soil in order to analyse the concept of subgrade reaction coefficient and its use in France to design retaining structures such as diaphragm walls. Then, we carry out a parameter study to analyse the effect of subgrade reaction coefficient, soil parameters c and φ and retaining wall stiffness on theoretical displacements and pressures behind anchored and self-stable retaining wall in the « DENEBOLA-LPC » software.

State-of-the-art requirements verification process applied to numerical finite-element modelling of the deep excavation in soft soils

“…Based on the measurements on sheeting structures in different soils and computation of a displacement of the structure needed to mobilize the limit value of active and passive pressure Chadeisson [ 59 ], Monnet [ 60 ] and Dhouib [ 61 ] derived expression for the determination of the active and passive horizontal modulus of subsoil reaction in the form: where: EI: bending stiffness of the structure [kNm 2 /m], γ: unit weight of soil [kN/m 3 ], K a : coefficient of active earth pressure, K p : coefficient of passive earth pressure [–], K 0 : coefficient of earth pressure at rest from Jaky formula [ 63 ], c’: effective cohesion of soil [kPa] and A c /A p : coefficient of influence of cohesion (1–15).…”

“…Examination of the results led him to identify four categories of structures, depending on the thickness of the soft seams, the safety factor of the settlement of the excavation bottom, and the rigidity of the support system. It is interesting to note that for the stations of the « Grand Paris Express », Daktera [46,47], Nejjar [48] and Burlon [49], give maximum horizontal displacements of the order of 15 to 20 mm for excavation depths close to 30 m, which gives a significantly lower u max /H ratio than the values found in previous references, of the order of 0.07% H. Several other works [50][51][52][53][54][55][56][57][58][59][60][61][62][63][64][65][66] in this area have…”

“…Based on the measurements on sheeting structures in different soils and computation of a displacement of the structure needed to mobilize the limit value of active and passive pressure Chadeisson [59], Monnet [60] and Dhouib [61] derived expression for the determination of…”

Major projects in urban sites: Challenge of the Builders

“…En effet, cette méthode permet de modéliser le sol en poussée et en butée contre l'écran de soutènement ( Figure 8) par des ressorts, comme le montre la figure 9. Figure 9 : Principe de la méthode du coefficient de réaction (Dhouib, 1995) L'avantage de la méthode aux coefficients de réaction réside dans sa simplicité de mise en oeuvre dans les calculs automatiques. Elle a l'inconvénient de supposer le sol « élastique » (Figure 10.a), alors qu'il en est guère (Figure 10…”

Major projects in urban sites: Challenge of the Builders

“…Principe de la méthode du coefficient de réaction(Dhouib, 1995) L'avantage de la méthode aux coefficients de réaction réside dans sa simplicité de mise en oeuvre dans les calculs automatiques. Elle a l'inconvénient de supposer le sol « élastique » (Figure 10.a), alors qu'il en est guère (Figure 10.b).…”