Earthquakes. & Expansive Soils

Transcription

1 Earthquakes & Expansive Soils January 22, 2009 Plan Update

2 Flanagan & Associates, LLC Consultants Tulsa, OK Plan can be reviewed at:

3 Overview of Process Step 1: Step 2: Step 3: Organize to Prepare the Plan Involve the Public Coordinate with Other Agencies and Organizations Step 4: Assess the Step 5: Assess the Problem (i.e., Specific Vulnerabilities) Step 6: Set Goals (i.e., Priorities Based Upon Assessments) Step 7: Review Possible Activities (i.e., Measures) Step 8: Step 9: Draft the Action Plan Adopt the Plan Step 10: Monitor, Evaluate, and Update Chapter 7

4 Earthquakes

5 Relative Risk of Earthquakes across the United States Earthquakes

6 Overview of the Richter Scale Scale Micro <2.0 Very Minor Minor Light Moderate Effects Microearthquakes, not felt Generally not felt, but recorded Often felt, rarely causes damage. Noticeable shaking of indoor items, rattling noises. Significant damage unlikely Can cause major damage to poorly constructed buildings over small regions. At most slight damage to well-designed buildings Earthquakes

7 Overview of the Richter Scale Cont. Scale Strong Major Great Massive Epic >10.0 Can be destructive in areas up to about 100 miles across in populated areas Can cause serious damage over larger areas Can cause serious damage in areas several hundred miles across Devastating in areas several thousand miles across Never recorded Effects Earthquakes

8 The Oklahoma Geological Survey reports a total of 6 earthquakes for Tulsa County from 1977 through 2005 Earthquakes

9 Earthquake Information All these quakes were smaller than 3.5 and produced no recorded damage Earthquakes

10 FEMA HAZUS-US Earthquake Scenario Results The largest magnitude earthquake to hit Oklahoma was a 5.7 Richter event centered near El Reno April 9, In a GIS environment the 5.7 Richter scale event was simulated on that historical point using FEMA-HAZUS-US software. 0 structures in would be impacted in any way by the results of this scenario, nor would any critical infrastructure be impacted in any negative fashion. Earthquakes

11 FEMA HAZUS-US Earthquake Scenario Results No fire stations or police stations would be operating at less than 50% capacity due to structural damages. No EOC would be adversely impacted by such an event. 2 a.m. is considered the peak residential load time. 0 injuries estimated will not require hospitalization, 0 injuries would require hospitalization and 0 deaths are estimated from this event. 0 people would seek temporary shelter from this event. Total economic loss is predicted to be $0 for such an event. Earthquakes

12 Measures 2004 Plan There were no chosen Earthquake Measures in 2004, other than building reinforcement for tornadoes and high winds ( Fortified Home ), which also protects against potential earthquake damage Fortified Home is a program of the Institute for Business & Home Safety (IBHS) Earthquakes

13 Goals & Objectives GOAL: To reduce injuries, loss of life, and damage to property, equipment and infrastructure caused by Earthquakes. 1. Public Information & Education. Improve public awareness of Earthquake hazards and measures by which people can protect themselves, their property and their community. 2. Preventive Measures. Identify and protect populations, structures, and critical infrastructure particularly vulnerable to Earthquakes, with consideration for uncalculated benefits such as averting environmental and business losses. Earthquakes

14 Goals & Objectives (cont.) GOAL: To reduce injuries, loss of life, and damage to property, equipment and infrastructure caused by Earthquakes. 3. Structural Projects. Provide for necessary construction, renovation, retrofitting or refurbishment to protect vulnerable structures from the effects of earthquakes. 4. Property Protection. Implement building materials and techniques in retrofitting or in new construction to minimize the risk to public properties and their occupants caused by Earthquakes. Earthquakes

15 Goals & Objectives (cont.) GOAL: To reduce injuries, loss of life, and damage to property, equipment and infrastructure caused by Earthquakes. 5. Emergency Services. Establish or expand emergency services protocols that adequately address Earthquake response. 6. Natural Resource Protection. Take advantage of opportunities for programs and policies that reduce negative environmental impacts. Examples include sustainable programs for debris management and recycling, and fortified construction with environmentally friendly materials. Earthquakes

16 Potential mitigation measures What are some additional measures we may adopt in 2009? Earthquakes

17 Potential additional Earthquake Public Information & Education Educate the public and builders to the fact that construction techniques for mitigating tornado damage also mitigate damage from minor earthquakes. Public Information & Education Provide information to the public on earthquake damage riders to their homeowner s s insurance. Earthquakes

18 Potential additional Earthquake (cont.) Property Protection Building reinforcements against wind and tornado damage will also protect against the minor earthquakes projected for the area. Emergency Services Develop a Debris Management plan which will assist in multiple types of hazards, including earthquake damage. Earthquakes

19 Fortified Home Institute for Business & Home Safety (IBHS) Structural Load Paths Earthquakes

20 Fortified Home Institute for Business & Home Safety (IBHS) Connection To Foundation, Slab On Grade Anchor Bolts Earthquakes

21 Fortified Home Institute for Business & Home Safety (IBHS) Wall To Foundation Earthquakes

22 Fortified Home Institute for Business & Home Safety (IBHS) Earthquakes

23 Fortified Home Institute for Business & Home Safety (IBHS) Connectors for roof system Earthquakes

24 Expansive Soils

25 Expansive Soils Introduction Soils and soft rock that swell or shrink due to changes in moisture content are known as Expansive Soils. Expansive soil is often referred to as swelling clay. Clay attracts and absorbs water. Dry clay will increase in volume as water is absorbed and decrease as it dries. Many factors control how much soil can swell, including type and concentration of minerals, density, amount of moisture change and restraining pressure of surrounding soil. The swell potential of soils beneath any particular property depends on local geology. The following maps were generated in a GIS environment using USDA Soil data viewer & its SSURGO (Soil Survey Geographic) Database. Expansive Soils

26 Expansive Soils in Action Soil sample with moderate shrink/swell potential Soil sample after the addition of a small amount of water Soil sample 48 hours later Expansive Soils

27 Oklahoma s s months of heavy rain followed by extended dry spells leads to an increased hazard from expansive soil damage Expansive Soils

28 Expansive Soils

29 Expansive Soils Source: National Resource Conservation Service (NRCS) Expansion Potential Very High Area (mi²) 2.9 Area (%) 11.4 High Moderate Low Water Expansive Soils

30 Expansive Soils Expansive Soils

31 6 Critical Facilities with Very High Expansive Soils Facility Name Bank of Oklahoma Bank of the West Fire Station #2 IBC Bank Address Warren Clinic (S. Memorial) YMCA Daycare Wilson Building Expansive Soils

32 4 Critical Facilities with High / Moderate Expansive Soils Facility Name Liberty Public School Midwest Childcare 8 Acres Camp Daycare Sand Plum Retirement Address High High Moderate Moderate Expansive Soils

33 Expansive Soils Future Growth Areas Expansion Potential Very High Area (mi²) 2.9 Area (%) 6.2% High Moderate % 32.73% Low % Water % Expansive Soils

34 Measures 2004 Plan Where do we stand on them? Develop and implement a public information strategy for informing citizens and the building industry of the dangers and costs to buildings of expansive soils. Identify and repair Critical Facilities that show or have expansive soils-related damage. Expansive Soils

35 Measures 2004 Plan Where do we stand on them? Investigate codes/incentives for the construction of new foundations i.e., pre-stressed, post-stressed, stressed, piered to avoid expansive soil problems. Expansive Soils

36 Goals & Objectives GOAL: To reduce the damage and economic losses caused by expansive soils on property and infrastructure. 1. Public Information & Education. Improve public awareness of expansive-soil soil hazards, with both general & site-specific specific information, & provide knowledge about available measures by which people can protect their property & their community. 2. Preventive Measures. Avoid expansive-soils soils locations, when possible. Explore options for loss-mitigation from expansive soils, including building codes & code-plus options. Examine soils before building critical facilities & infrastructure. Expansive Soils

37 Goals & Objectives (cont.) GOAL: To reduce the damage and economic losses caused by expansive soils on property and infrastructure. 3. Structural Projects. Identify and implement measures to reduce or avert expansive-soils soils damages and losses to structures and infrastructure, with emphasis on critical facilities and utilities. 4. Property Protection. Identify and protect resources and critical infrastructures that are vulnerable to expansive soils. Expansive Soils

38 Goals & Objectives (cont.) GOAL: To reduce the damage and economic losses caused by expansive soils on property and infrastructure. 5. Emergency Services. Survey emergency and critical facilities for potential expansive soil problems; repair and retrofit as needed; and consider soils when building emergency facilities. 6. Natural Resource Protection. Protect and enhance natural resources by adopting and implementing sustainable expansive soils policies that have few or no negative impacts and have positive environmental effects when possible. Expansive Soils

39 Potential mitigation measures Which 2004 measures do we keep? What are some additional measures we may adopt in 2009? Expansive Soils

40 Potential additional Expansive Soils Public Information & Education Inform homeowners of landscaping measures, such as xeriscaping, drainage systems or ground sloping, that can mitigate foundation damage Preventive Measures Establish a procedure to inform builders when they apply for permits to check for expansive soils Expansive Soils

41 Potential additional Expansive Soils (cont.) Preventive Measures Educate builders on appropriate foundation types for soils with different degrees of shrink-swell swell potential. For example, using post-tensioned tensioned slab-on on-grade or drilled pier vs. standard slab on grade or wall on grade foundations. Expansive Soils

42 Educate local builders, homeowners, and homebuyers on appropriate building techniques for expansive soils Expansive Soils

43 Vulnerability Analysis Type of Occurrence History Prob Hum Impact Prop Infra Bus Mit n Activities Resources Int. Ext. Total Dam/Levee Drought Earthquake Expansive Soils Flooding Hail HazMat, Fixed Heat High Wind Lightning Tornadoes Transportation Urban Fires Wildfires Winter Storm

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45 Questions or Comments? Plan can be reviewed at: