Safety Assessment Program Evaluator Student Manual

More documents

Recommendations

Info

CA Emergency Mgmt. Agency Safety Assessment Program Evaluator Manual April 2011It was stated earlier that 114,000 households needed some form of housing assistance. Thesewere households, not structures. For instance, there are multiple households within an apartmentbuilding, but only one residential structure. (The fact that the number of safety assessments andthe number of households needing housing assistance are the same is only a coincidence.)There are structures that are tagged RESTRICTED USE that reasonably might be occupied,while respecting the restrictions. Some residences suffer cripple wall collapse, and normallythey would not be habitable due to the loss of water and sewer connections; but a communitycould allow occupancy under RESTRICTED USE if potable water and portable toilet stationswere provided by the community for those so affected. Other communities will not permit anyoccupancy of homes damaged in this manner, regardless of the resource made available. This isa local government decision, and whatever decision is made by the local Building Official orothers, it must be respected.3.2 Mobile Homes and Manufactured HomesThe installation and alteration of mobile homes or manufactured homes is regulated in Californiaby the Department of Housing and Community Development (HCD). Mobile homes can behazardous after a disaster because of damaged utilities, foundational support systems, oraccessories such as awnings, carports, porches, and room additions.After the 1994 Northridge Earthquake, HCD and the California Building Officials (CALBO)began discussions on how to supplement HCD inspectors in order to ensure that mobile homeswere evaluated properly. An agreement came out of these discussions that grants the localbuilding officials with the authority to evaluate the safety of mobile homes following anearthquake or other disaster. The agreement stipulated that Cal EMA include a section onmobile homes in this training program.A mobile or manufactured home may be looked at more quickly than other types of structures;this is the main difference in evaluating them, as opposed to other residences. The evaluationcriteria is otherwise very similar to that for other single family residences.Damage to mobile homes or manufactured homes falls generally into these basic types:The mobile home is partially or completely fallen off its foundation elements, whetherthese be piers, blocks, or jack standsPiers are penetrating the interior floor deckingMobile home is partially or completely burnedUtilities are damaged and/or turned offWater heater movement has affected the water heater vent and/or gas supplyThe mobile home accessories (decks, awnings, carports, garages, etc.) are destroyed orhazardousAfter the Landers-Big Bear Earthquakes of 1992, requirements for mobile home foundationconstruction were improved such that new construction must create a positive foundationconnection to the ground. This should work to reduce, if not eliminate, much of the damagefrom earthquakes for new construction. However, many units remain grandfathered in their priorconditions and remain at risk.80
CA Emergency Mgmt. Agency Safety Assessment Program Evaluator Manual April 2011Lateral motion induced failure of mobile home foundations can be easily mitigated by theinstallation of seismic bracing under the mobile home, thereby restricting the free movement ofthe unit on its jack stands. Such bracing stabilizes the unit and provides transmission of thelateral force load path into the ground.There are many ways in which mobile homes can be braced; the more common systems are steelmembers installed diagonally in two directions under the unit. Another method is to provide afixed foundation, and anchor the unit to the foundation.Following the 1994 Northridge Earthquake, the Governor‟s Office of Emergency Services (OES)instituted a program with FEMA support to install seismic bracing under all mobile homes thatwere damaged by the earthquake.Seismic bracing significantly reduces the risk of damage to mobile homes caused byearthquakes; however, thousands of units remain throughout California that do not have seismicbracing.The process and procedure for evaluating mobile homes is the same as for any other structure.However, it is important to keep in mind that mobile home parks may present some uniquehazards due to post-disaster damage. Many mobile home parks are like small cities, with masterelectrical, gas, water, and sewer systems. Therefore, SAP evaluators are encouraged to watch forthe hazards that these systems may pose if compromised.For example, energized overhead electrical systems may fall on metal roofed mobile homes,energizing the entire exterior. Gas line breaks both underground and under mobile homes canpose both an access and a safety problem. Large waterline breaks within mobile home parks canundermine roads and homes, and deactivate fire hydrants, creating an additional fire risk. Caremust be taken by SAP evaluators to watch for hazards and avoid dangerous situations.3.2.1 Evaluation ProceduresWhen evaluating mobile homes, concentrate efforts in the following areas:Stability of the jack standsSafety of the unit‟s accessories, such as awnings, carports, etc.Condition of the utilitiesHome ingress and egressGeotechnical issues (liquefaction, lateral spreading, etc.)Since mobile homes are relatively light and strong, there is usually no problem with thestructural system. The mobile home tends to respond as a single unit. However, in anearthquake it is not uncommon for fallen units to sustain chassis damage, and for doublewides tohave movement at their centerline connection and even partial separation.Without any lateral force restraint such as seismic bracing, the movement will cause thefoundational jack stands or supports to tip over or collapse. This could be all of the jack stands,causing the mobile home to fall to the ground, or just some of the jack stands, which may leavethe mobile home in a partially fallen (and unstable) position.81
Page 1 and 2:
CA Emergency Mgmt. Agency Safety As
Page 3 and 4:
Page 5 and 6:
Page 7 and 8:
Page 9 and 10:
Page 12 and 13:
Page 14:
Page 17 and 18:
Page 19 and 20:
Page 24 and 25:
Page 26 and 27:
Page 28 and 29:
Page 31 and 32: CA Emergency Mgmt. Agency Safety As
Page 79: CA Emergency Mgmt. Agency Safety As
Page 130 and 131:
Page 132 and 133:
Page 134 and 135:
Page 136 and 137:
Page 138 and 139:
Page 140 and 141:
Page 142 and 143:
Page 144 and 145:
Page 146 and 147:
Page 148 and 149:
Page 150 and 151:
Page 152 and 153:
Page 154 and 155:
Page 156 and 157:
Page 158 and 159:
Page 160 and 161:
Page 162 and 163:
Page 164 and 165:
Page 166 and 167:
Page 168 and 169:
Page 170 and 171:
Page 172 and 173:
Page 174 and 175:
Page 176 and 177:
Page 178 and 179:
Page 180 and 181:
Page 182 and 183:
Page 184 and 185:
Page 186 and 187:
Page 188 and 189:
Page 190 and 191:
Page 192 and 193:
Page 194 and 195:
Page 196 and 197:
Page 198 and 199:
Page 200 and 201:
Page 202 and 203:
Page 204 and 205:
Page 206 and 207:
Page 208 and 209:
Page 210 and 211:
Page 212 and 213:
Page 214 and 215:
Page 216 and 217:
Page 218 and 219:
Page 220 and 221:
Page 222 and 223:
Page 224 and 225:
Page 226 and 227:
Page 228 and 229:
Page 230 and 231:
Page 232 and 233:
Page 234 and 235:
Page 236 and 237:
Page 238 and 239:
Page 240 and 241:
Page 242 and 243:
Page 244 and 245:
Page 246 and 247:
Page 248 and 249:
Page 250 and 251:
Page 252 and 253:
Page 254 and 255:
Page 256 and 257:
Page 258 and 259:
Page 260 and 261:
Page 262 and 263:
show all

Safety Assessment Program Evaluator Student Manual

Create successful ePaper yourself

Delete template?

Save as template?