%0 Book Section %1 statphys23_0270 %A Kadau, D. %A Jr., J.S. Andrade %A Herrmann, H.J. %B Abstract Book of the XXIII IUPAP International Conference on Statistical Physics %C Genova, Italy %D 2007 %E Pietronero, Luciano %E Loreto, Vittorio %E Zapperi, Stefano %K contact dem dynamics effects memory quicksand shear statphys23 strength topic-7 %T Quicksand: New insights on nature and danger %U http://st23.statphys23.org/webservices/abstract/preview_pop.php?ID_PAPER=270 %X The nature and danger of quicksand has been disputed since a long time. Despite widespread belief that humans can be swallowed or even sucked in, engineers of soil mechanics have typically asserted that, since the density of sludge is larger than that of water, a person cannot fully submerge. We investigated a specific type of quicksand at the shore of drying lagoons. Cyanobacteria form an impermeable crust, giving the impression of stable ground. After breaking the crust a person rapidly sinks to the bottom of the field. We measured the shear strength of the material before and after perturbation and found a drastic change. To undermine our point that objects lighter than water can be swallowed in the quicksand, we simulated a model in which we constructed a tenuous granular structure representing the unperturbed soil. The initial structure consists of cohesive disks put together by ballistic deposition and settled by gravity using Contact Dynamics. Pushing in an object leads to breaking of cohesive bonds. We investigate how deep the object can be pushed in and how well the intruder is captured by the soil after it collapsed above the intruder.

@incollection{statphys23_0270, abstract = {The nature and danger of quicksand has been disputed since a long time. Despite widespread belief that humans can be swallowed or even sucked in, engineers of soil mechanics have typically asserted that, since the density of sludge is larger than that of water, a person cannot fully submerge. We investigated a specific type of quicksand at the shore of drying lagoons. Cyanobacteria form an impermeable crust, giving the impression of stable ground. After breaking the crust a person rapidly sinks to the bottom of the field. We measured the shear strength of the material before and after perturbation and found a drastic change. To undermine our point that objects lighter than water can be swallowed in the quicksand, we simulated a model in which we constructed a tenuous granular structure representing the unperturbed soil. The initial structure consists of cohesive disks put together by ballistic deposition and settled by gravity using Contact Dynamics. Pushing in an object leads to breaking of cohesive bonds. We investigate how deep the object can be pushed in and how well the intruder is captured by the soil after it collapsed above the intruder.}, added-at = {2007-06-20T10:16:09.000+0200}, address = {Genova, Italy}, author = {Kadau, D. and Jr., J.S. Andrade and Herrmann, H.J.}, biburl = {https://www.bibsonomy.org/bibtex/225915d789b18376e51e67bbf203245d2/statphys23}, booktitle = {Abstract Book of the XXIII IUPAP International Conference on Statistical Physics}, editor = {Pietronero, Luciano and Loreto, Vittorio and Zapperi, Stefano}, interhash = {9a4684203918452ed764cd82165d6476}, intrahash = {25915d789b18376e51e67bbf203245d2}, keywords = {contact dem dynamics effects memory quicksand shear statphys23 strength topic-7}, month = {9-13 July}, timestamp = {2007-06-20T10:16:15.000+0200}, title = {Quicksand: New insights on nature and danger}, url = {http://st23.statphys23.org/webservices/abstract/preview_pop.php?ID_PAPER=270}, year = 2007 }