Laserfiche WebLink
<br />. <br /> <br />Minimum recommended values of FSP are given in <br />Table S-1. A faclOr of safety FSA may be applied fer <br />active pressures. however il is considered sufficienl 10 <br />use an FSA .. I in mosl cases unless defonnations of <br />Ihe wall are resuicled. <br /> <br />Tell.. 5-1 <br />Minimum Salety F...1oIs lor Delermlnlng the Depth <br />01 P......lion Appllecllo the P_IYtI P....u... <br /> <br />l.oe<Ing Case Fine-Grain So~. F....Olaining Soil. <br /> <br />Floodwllll. <br /> <br />Usual 1.50 Q-C... 1.50 S-C... <br /> 1.10 S-C... <br />Unuaual 1.25 Q-Case 1.25 S-C... <br /> 1.10 S-C... <br />Extrarna 1.10 Q-Ca.. 1.10 S-C... <br /> 1.10 S-C... <br /> <br />Retaining Willi. <br />Usulll 2.00 Q-Case 1.50 S-C... <br /> 1.50 S-C... <br />Unuaulll 1.75 Q-Case 1.25 S-C... <br /> . 1.25 S-C... <br />Exlrama 1.50 Q-C.se 1.10 S-C... <br /> 1.10 S-C... <br /> <br />. <br /> <br />e. Net pressure distribulions. Evaluations of Ihe <br />pressures by Ihe processes described in Chapler 4 resull <br />in a number of pressure dislributions. <br /> <br />(1) Active soil pressures due 10 relained side soil. <br /> <br />(2) Passive soil pressures due 10 relained side soil. <br /> <br />(3) Pressures due 10 surcharge loads on retained <br />side surface. (Effects of surcharge loads are included in <br />!he soil pressures when a wedge melhod is used.) <br /> <br />(4) Active soil pressures clue 10 dredge side soil. <br />(S) Passive soil pressures due 10 dredge side soil. <br /> <br />. . <br /> <br />(6) Pressures due 10 surcharge loads on dredge side . <br />surface. <br /> <br />(7) Net water pressures due 10 differential head. <br /> <br />. <br /> <br />EM 1110.2.2504 <br />31 Mar 94 <br /> <br />For convenience in calcu1alions for S18bility. !he <br />individual disbibutions are combined inlo "net" pressure <br />diSlributions according 10: <br /> <br />"NET ACTIVE" PRESSURE .. relained side active <br />soil pressure <br />- dredge side passive soil <br />pressure <br />+ nel waler pressure <br />(+ pressure due 10 <br />relained side surcharge) <br />(- pressure due 10 dredge <br />side surcharge) <br /> <br />"NET PASSIVE" PRESSURE.. relained side passive <br />soil pressure <br />- dredge side active soil <br />pressure <br />+ nel waler pressure <br />(+ pressure due 10 <br />relained side surcharge) <br />(- pressure due 10 dredge <br />side surcharge) . <br /> <br />In Ihese defmitions of nel pressure disbibutions, positive <br />pressures lend 10 move Ihe wall toward !he dredge side. <br />Typical nel pressure diagrams areiJIUSlraled in <br />Figure S-S. <br /> <br />f Stability design for cantilever walls. II is assumed <br />thai a cantilever wall roIaIeS as a rigid body about some <br />poinl in its embedded lenglh as illusttaled in Fig- <br />ure S-2a. This assumption implies thai the wall is <br />subjecled 10 Ihe nel active pressure distribution from Ihe <br />top of the wall down 10 a poinl (subsequently called Ihe <br />"transition poinl") near Ihe poinl of zero displacemenL <br />The design pressure distribution is then aSsumed 10 vary <br />linearly from Ihe nel active pressure at the ttansition <br />poinl 10 !he full net passive pressure at !he bollom of <br />the wall. TIre design pressure distribution is illustrated <br />in Figure S-6. Equilibrium of Ihe wall requires thaI Ihe <br />sum of horizontal forces and Ihe sum of moments aboul <br />any point musl boIh be equa1 10 zero. . The !wo <br />equilibrium equations. may be solved for Ihe location of <br />. the ttansition poinl (i.e. !he dislanCe z in Figure 5-6) and <br />!he required depth of penelnllion (distance d in Fig- <br />ure S-6). Because !he simullaneous equations are non- <br />linear in z and d, a lriaI and ~ solution is required. <br /> <br />g. Stability design for anchored walls, Several <br />melhods flr anchored wall design have been proposed <br /> <br />5-5 <br />