Arching in Distribution of Active Load on Retaining Walls

Abstract

Traditional methods for calculations of active loads on retaining structures provide dependable forces, but these methods do not indicate reliably the location of the resultant load on the walls. The Coulomb method does not address the load distribution because it utilizes equilibrium of forces, whereas the Rankine stress distribution provides linear increase of the load with depth. Past experimental studies indicate intricate distributions dependent on the mode of displacement of the wall before reaching the limit state. The discrete element method was used to simulate soil-retaining structure interaction, and force chains characteristic of arching were identified. Arching appears to be the primary cause affecting the load distribution. A differential slice technique was used to mimic the load distributions seen in physical experiments. The outcome indicates that rotation modes of wall movement are associated with uneven mobilization of strength on the surface separating the moving backfill from the soil at rest. Calculations show that the location of the centroid of the active load distribution behind a translating wall is approximately 0.40 of the wall height above the base, but for a wall rotating about its top point, the location of the resultant is at approximately 0:55H. In the third case, rotation about the base, the location of the calculated centroid of the stress distribution on the wall is slightly below one-third of the wall height.

Numerical and theoretical research on stress distribution in the loosening zone of the trapdoor problem

“…The objective of this paper is to study the stress redistribution in the loosening zone of a trapdoor problem with confined granular matter by numerical and theoretical analysis. A series of numerical models of trapdoor tests are established through the DEM, which has been widely used in the research of arching effect in granular matter . The stress states in the loosening zone are recorded in the process of the numerical trapdoor test.…”

Design Guideline Basal Reinforced Piled Embankments

“…The CA model therefore provides a physical explanation for the observed load distribution. The concentric stress arches have also been found by several authors presenting numerical studies on arching such as Vermeer et al (2001), Nadukuru and Michalowski (2012), Han et al (2012) and . The Concentric Arches model explains how arching increases with subsoil consolidation (GR deflection): new arches are formed in succession as GR deflection progresses.…”

“…Furthermore, the inverse triangle (or at least the concentration of load close to the piles, and the minimum load in the centre between piles) was also found in, for example, finite element calculations on a soldier pile wall by Vermeer et al (2001), discrete element calculations on a heap of grains on a deflecting subsurface (Nadukuru and Michalowski, 2012), numerical calculations by Han et al (2012), with a inversed triangle in their Figure 9, and by Den Boogert et al (2012a,b), settlement measurements in a field test 2013) and the large-scale model tests of Filz and Sloan (2013 GR also has a major effect on ground pressure in the fill above the GR between the piles. Zaeske (2001, pages 55 and 63) showed that this ground pressure declines with increasing fill depth.…”

“…Another example is Nadukuru and Michalowski (2012), who carried out discrete element simulations. After a wedge-shaped heap of particles was formed, a basal deflection was prescribed.…”

Numerical investigation into the failure of a micropile retaining wall

“…[3][4][5][6][7][8][9][10][11][12][13][14][15][16]. The behaviour and failure of embedded or anchored in situ retaining walls has been extensively investigated as well in recent years [17][18][19][20][21][22][23][24][25]. A satisfactory performance of this type of structures requires sufficient knowledge of the geometric, topographic, hydrologic and geologic characteristics of the site, and of the material properties of the ground.…”