Performance of Pipes During Earthquakes

Transcription

1 Performance of Pipes During Earthquakes March 28-31, 2011, Long Beach, CA Camille George Rubeiz, PE Director of Engineering, Plastics Pipe Institute Japan March 2011 EQ: Failures in pipelines have often resulted in the failure of the overall water supply system due to rapid loss of water draining the reservoirs;

2 Outline Performance of Pipes During Earthquakes Earthquakes in Japan, CA and Columbia Tsunami in Thailand Non-Earthquake data from UK, Sweden and US Lessons Learned/Summary Intensity a number (written in Roman numeral) describing the severity of an E Qauke per its effects on the earth's surface, humans and structures. Where as Intensity is location dependent, magnitude is one number for each earthquake. Magnitude is a number that characterizes the relative size of an E Quake. based on measurement of the maximum motion recorded by a seismograph. Richter scale is most common/known/used

3 Every state has experienced an earthquake (EQ) There is 100% chance of an earthquake today USGS It is not feasible to design or rehab a water / wastewater system to be EQ-proof

4 CA and HI have experienced the 4 th largest magnitude EQ in US history with magnitude of 7.9 NV experienced the 6 th largest EQ in US with magnitude of 7.2 The 7.9 EQ (CA) is 5 times bigger in magnitude than the 7.2 NV EQ Only MO (8), AR (8.2), AK (9.2) experienced higher magnitude EQ In addition to loss of water, in case of power loss, the reservoirs cannot be refilled and water is not available for fire suppression as occurred in Kobe, Loma Prieta, Northridge and San Francisco

5 Communication from Japan Water Works Association sent March 23 to AWWA Executive Director David LaFrance 1. Japan Water Works Association (JWWA) helps utilities restore water service in quake, tsunami area: Magnitude: 9 (revised), March 11, 2011 at 2:46pm at epicenter, 231 NE of Tokyo JWWA and water utilities working to repair damaged pipes Number of households without water March million March ,000

6 Communication from Japan Water Works Association sent March 23 to AWWA Executive Director David LaFrance picture AWWA website Japan JWWA. Most urgent task- helping people access tap water, followed by researching areas without water service and determining a plan for recovering service in the future Dispatched trucks with water tank- Acquired 462 trucks and put 311 trucks in service.

7 Failures/ KM Earthquakes 2. Great Hanshin Awaji (Kobe) Earthquake in Japan (Honda, PP X, Sweden) 1995: Magnitude 6.9 and 1,600 leaks from water distribution Over 75% of Kobe s households without water ASCE 2002 Leaks due to joint separation (63%), broken pipe (20%) and fixtures (17%) Kobe E'Quake Water pipe Gas pipe 0 PE Steel DCIP PVC CIP AC

8 3. Long Beach, CA March 10, 5:54pm PST Mag moderate (Japan EQ= 398xLB EQ) Shocks similar in magnitude and intensity occurred in this area in 1769,1812, 1855, 1933,?? Damage: $40 million property and 115 pp killed School buildings were most commonly and severely damaged- led to Field Act which regulates building construction practice in CA

9 Long Beach, California. San Pedro Wharf. 10 inch iron salt water line to fuel oil coolers separated 5 and 3/4 inches. Broken companion flange pulled out threads. USGS ID. Anonymous, 551 amn California%2C+Earthquake+March+10%2C+1933%7CLong+Be ach%7cearthquake%7c1933

10 4. Loma Prieta Earthquake and Gas Pipes (Philips and Virostek 1990) 1989: Magnitude 7.1 earthquake, about 60 miles south of San Francisco. (Japan EQ = 79 x LM EQ) Damage: The number of leaks that can be attributed to the earthquake is unknown (inconsistent and incomplete docs) PG&E Grade 1 Leaks in Gas Distribution Mains and Gas services Type of Pipe Failure Ratio (Leaks/100mile Mains) Failure Ratio (Leaks/100 services) PE Cast Iron Steel

11 Repair rate/km ASCE 1999 p 69 (AC =Asbestos Cement; C=Concrete; CI=Cast Iron, WI=Wrought Iron; DI= Ductile Iron; WS=Welded Steel- type of Joint is shown between ( ) Loma Prieta 0.6 Nihonkai AC, C, CI, WI (lead) PVC (Gask) CI (Gask) DI (Mech) DI (Gask) WS (lap welded)

12 4. Loma Prieta Earthquake (Ted Harrington, PE, Performance of Pipelines during the Loma Prieta Earthquake, Unpublished, presented at AWWA CA-NV (Santa Rosa) and NACE Corrosion 90 (Las Vegas), both April 1990) Much of the analysis drawn from the Marin Municipal District 30 water pipeline failures (26 CI and 4 bare steel) Estimated loss of 2 million gallons of water Original water system CI and was failing; in 1965, system pressure was lowered and a replacement program began using AC, PVC and CP welded steel; no piping failure occurred in a mobile home park that installed (1970) PVC and steel.

13 Effects of Earthquakes on Pipes 4. Loma Prieta Earthquake (Ted Harrington, PE,.) Pipes that did not fail were CP metal and non-metallic pipes Corrosion- showed hazard of relying on coating alone for corrosion protection.. corrosion can be eliminated as an economic waste through the use of non-metallic piping, protective coatings and cathodic protection.

14 5a. Northridge EQ: Effects on Water Pipes (AWWA 1994, ASCE 1999). 1994: major EQ with a magnitude of 6.8, about 20 miles from Los Angeles (Japan EQ=158 x Northridge) Damage: 3 transmission pipes that deliver water from N. CA Damage: Over 1,500 leaks in the water system of the San Fernando and San Clarita valleys. Swimming pools used for emergency fire fighting ASCE 2002 If this occurred elsewhere in N. America, the water system would have been more heavily damaged (system upgraded due to 1971 San Fernando EQ (mag. 6.5).

15 5b. Northridge Earthquake and Gas Pipes (Lucas 1994) Southern California Gas Co. operates 84,000 miles of distribution piping and 3,300 miles of transmission piping. 209 minor and significant leaks in the lower pressure, smaller diameter distribution system Also, 500 leaks were classified as related to earthquake Damage: Majority in older steel pipe where minor corrosion conditions were accelerated by the seismic stress Damage: 35 leaks in the transmission system (majority in 1930s steel) Damage: 27 in PE pipe

16 5b. Northridge Earthquake and Gas Pipes (Lucas 1994) Several measures contributed to the excellent performance of the piping system... One of the measures is the use of plastic pipe (PE). Since 1969, the Company has installed plastic pipe wherever possible. Today (i.e. 1994) about 41% of our distribution system utilizes plastic pipe, which is less subject to earthquake damage. Also, the experience of the Company (SoCalGas) and PG&E in San Francisco is that PE is one of the best materials available because of its high ductility and ability to resist deflections from ground movement.

17 Failures/ 10 KM Earthquakes 6. Columbia (Bresser, 2000, p. 7). January 25, 1999 earthquake in Armenia, Columbia Magnitude 5.9 Moderate earthquake and caused extraordinary damage Columbia E'Quake PE RC DI PVC AC CI

18 Damage Mechanisms: can be categorized to include: 1. Wave Propagation (WP): (AWWA 1994, p ) In almost all cases, continuous arc welded steel or polyethylene pipe has adequate ductility to accommodate wave propagation ground strains with no damage. 2. Permanent Ground Deformation (PGD): (p. 41) Higher failure rates than from wave propagation Corrosion can also lead to failures from WP and PGD 3. Fault Rupture: (p. 42) Pipelines in the low-vulnerability category will perform the best when fault movement occurs.

19 AWWA Minimizing Earthquake Damage, A Guide to Water Utilities, BS = Bell & Spigot; RG = Rubber Gasket; RES= Restrained; ND = No Designation Low Vulnerability Ductile Iron AWWA C1xx BS, RG, RES PE AWWA C906 Fused Steel AWWA C2xx Arc welded; BS, RG, RES Steel ND Riveted Low to Moderate Concrete Cyl. AWWA C300, C303 BS, RES Ductile Iron AWWA C1xx BS, RG, Un RES PVC AWWA C900, C905 BS, RES

20 AWWA Minimizing Earthquake Damage, A Guide to Water Utilities, BS = Bell & Spigot; RG = Rubber Gasket; RES= Restrained; ND = No Designation Moderate Vulnerability Asbestos C. (>8 ) AWWA C4xx Coupled Cast Iron (>8 ) ND BS, RG PVC AWWA C900, C905 BS, Un-RES Steel AWWA C2xx BS, RG, Un-RES Moderate to High Asbestos C (<=8 ) AWWA C4xx Coupled Cast Iron (<=8 ) ND BS, RG Concrete C AWWA C300, C303 BS, Un-RES Steel ND Gas Welded High Cast Iron ND BS, leaded or mortared

21 Tsunami Thailand Tsunami (ASCE 2005; Curtis Edwards, P.E., Vice President, Pountney Psomas Thailand Team Leader, ASCE ) Prevalent use of HDPE piping for potable water. Much of this (HDPE) piping was exposed to erosion and subjected to harsh conditions from debris and waves. The HDPE piping performed very well with few failures. The material is flexible, allowing it to conform to new contours after the erosion. It is also very light, making repairs very easy.

22 Failures per 10km Non-EQ Performance UKWIR NATIONAL FAILURE DATABASE ( ) PE DI PVC STL AC CI Material Group Failure statistics for the Swedish water pipe network 1986 Failures per 10km PE DI PVC CI STL Materials

23 Non-EQ Performance Water Main Break Data per 100KM, H/bk of PVC Pipe, Unibell, p. 167 Assessment of Historical Main Break Data, Michael Brown, Gannett Fleming, Linda Bridwell, KY American Water,, AWWA ACE CI AC DI PVC no longer installed installed today Breaks per 100 KM

24 Lessons Learned / Summary Pipe EQ damage is influenced by: (ASCE 1999, p. 60) The more ductile the material, the lower the damage rate. Thin wall ductile material is susceptible to corrosion which can offset the benefits of ductility. Pipelines constructed from brittle materials are the most vulnerable because they are not able to bend and flex USGS Corrosion on metal pipes increases pipe damage rate. Larger diameter pipes appear to have lower damage rates than smaller small diameter pipe. Lower damage rate may be a function of lack of attachments, placement in better soil, more careful design and construction practices, thicker walls

25 Lessons Learned / Summary Pipe EQ damage is influenced by: (ASCE 1999) Design for system flexibility and redundancy Rigid joint material cause higher damage rates than flexible joint material. Joint pullout and crushing possible with slip on segmented pipe. Use Restrained Joints rather than thrust blocks to resist thrust. Thrust blocks may move if liquefaction occurs. Fittings (and joints) should be as ductile and as strong as the pipe material

26 Lessons Learned / Summary ASCE and AWWA tabulated the vulnerability of pipes to EQs: Lowest vulnerability: PE -fused joint, DI & Steel - restrained Low to Moderate: DI -unrestrained; concrete cylinder & PVCrestrained Moderate: Steel and PVC -unrestrained Moderate to High: Cast Iron and Vitrified Clay High: Steel- gas welded; Concrete- unrestrained; CI -leaded or mortared; VC (rigid); Asbestos Cement (Coupled) All joints are Bell and Spigot with Rubber Gasket, UNO

27 Thank you for your time and for your invitation to your Spring meeting Also, I want to thank the chair of the Water Distribution Division, Mr. Stephen Gay, Long Beach Water Dept., and Chair of the Materials Performance Cmt., Mr. Mike Gravitt, Sweetwater Authority for organizing this session Appreciate receiving additional published data; pls to crubeiz@plasticpipe.org