MR. TOM OSTROM October 21, 2014 Page 2

LITERATURE REVIEW

The Raymond fault is a left-lateral strike-slip fault. It was considered to be a thrust fault until the early 1990’s (Jones et al., 1990). The fault acts as a groundwater barrier. North of the fault, groundwater lies approximately 100 feet below the ground surface, while south of the fault, groundwater lies approximately 400 feet below ground surface (Bryant, 1978). Fault features are shown on Figure 3 (Bryant, 1978), and on a 1953 topographic map with 5’ contour intervals (Figure 4). The fine topographic contours on Figure 4 clearly show the fault scarp north of State Route 110 described by multiple workers (Bryant, 1978), as well as offset in the drainage that marks the municipal boundary of the City of San Marino.

Alquist-Priolo Earthquake Fault Zone Map

The Alquist-Priolo Earthquake Fault Zone Map (1977; Figure 2 shows a single, approximately located strand of the fault immediately north of State Route 110, at the southern base of a south- facing scarp. At Grand Avenue, the fault bifurcates.

Bryant, 1978

Bryant (1978) described the expression of the Raymond fault. At the time of the earliest descriptions of the Raymond fault, Los Angeles County had already been heavily developed. Bryant (1978) shows the 1939 construction of State Route 110 and the approximate location of the Raymond fault between Orange Grove Avenue and Fair Oaks Avenue (Figure 3).

Weaver and Dolan, 2000

Weaver and Dolan (2000) excavated two paleoseismic trenches along the Raymond fault within a few kilometers of the bridge site. They reported ages of the most recent events and total slip on the fault, but did not report any empirical offsets from the most recent event.

Bridge Inspection Reports

The latest Bridge Inspection Report (February 2013) does not describe any damage that is consistent with fault creep or fault offset.

Site Visit

Gustavo Ortega (Senior Engineering Geologist - Geotechnical Design South) visited the site in October, 2014, and measured site-to-source distances for seven bridges on State Route 110. The fault was identified by using the 1939 air photo shown in Figure 3, and measuring to the base of the fault scarp north of State Route 110. The distances were measured from the north limit of the

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MR. TOM OSTROM October 21, 2014 Page 3

bridge deck to the Raymond Fault using a handheld Laser Rangefinder. The distance for the Grand Avenue structure was measured following the trend of the fault depicted in the 1939 aerial photograph to the east. At the Grand Avenue OC, the scarp lies approximately 62 m north of the edge of the bridge deck.

Literature Review - Conclusions

Much of Los Angeles County was developed before widespread use of the mechanical grader became common, and fault scarps are still present, largely undestroyed. The east-west-trending Raymond fault is expressed in South Pasadena as a south-facing scarp, clearly visible on the 1953 topographic map with 5’ contour intervals (Figure 4). The construction of the east-west portion of State Route 110, finished in 1940, at least partially destroyed the expression of the Raymond fault, but for much of this east-west stretch of State Route 110, a fault scarp lies north of the highway.

CALCULATIONS OF EXPECTED OFFSET

To quantify potential fault offset, I used a spreadsheet (version 9, May, 2014) developed by the Division of Research and Innovation in collaboration with Geotechnical Services, based upon methods presented in Petersen, et al. (2011), and Abrahamson (2008). Both a deterministic fault displacement analysis and a probabilistic fault displacement analysis were performed. The input parameters included maximum magnitude, slip rate, mapping and base map errors.

Mmax

1 The Mmax of 6.7 is cited in the Caltrans fault database , which references the USGS (2008).

Slip Rate

In this report we use the slip rate from Dawson and Weldon (2012) of 2 mm/year. No creep is reported on this fault.

Empirical Slip Measurements

No empirical slip measurements were incorporated into this analysis.

Site-to-Source Distance

The fault lies approximately 62 m north of the bridge deck.

1 CT fault database: http://dap3.dot.ca.gov/shake_stable/v2/technical.php “Provide a safe, sustainable, integrated and efficient transportation system to enhance California’s economy and livability”

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Type of Slip

The Raymond fault is a left-lateral strike-slip fault. The fault lies sub-parallel to the bridge footprint.

Table 1 Offset Calculation Inputs Input Value Source Raymond fault 100 % State of California, 1977 Site-to-Source Distance 62 m Field Measurement, State of California, 1977, USGS, 1953 Mmax 6.7 CT fault database2; USGS (2008) Map Quality Approximate, State of California, 1977 simple Slip Rate 2 mm/year CT fault database, Dawson and Weldon (2012) Empirical Slip Measurements None Type of Slip left-lateral strike- CT fault database; USGS (2008) slip Probabilistic Offset, 975 year 0.18 m (7 inches) return Deterministic Offset 0.2 m (7 inches)

Calculated Potential Offset at the Bridge

The deterministic offset calculation results are shown in Figure 5. The probabilistic calculation results are shown in Figure 6.

RECOMMENDATIONS

No further geologic work is recommended at this time. If you have any questions, please contact Anna Sojourner at (510) 622-8839.

c: TPokrywka, CRisden, GOrtega, DCook, FAlmeddine, TShantz, Daily File ASojourner/mm Attachments: Figures 1 – 5

2 CT fault database: http://dap3.dot.ca.gov/shake_stable/v2/technical.php “Provide a safe, sustainable, integrated and efficient transportation system to enhance California’s economy and livability”

MR. TOM OSTROM October 21, 2014 Page 5

REFERENCES

Abrahamson, N., 2008, Appendix C, Probabilistic Fault Rupture Hazard Analysis, San Francisco Public Utilities Commission, General Seismic Requirements for the Design on New Facilities and Upgrade of Existing Facilities Bryant, W.A., 1978, The Raymond Hill fault, an Urban Geological Investigation: California Geology, v. 31, no. 6, p. 127-142. California Geological Survey, 2002, Guidelines for evaluating hazard of surface fault rupture, CGS Note 49, 4p: http://www.conservation.ca.gov/cgs/information/publications/cgs_notes/note_49/Docume nts/note_49.pdf Caltrans, 2013, Memo to Designers 20-10, Fault Rupture: http://onramp.dot.ca.gov/hq/esc/sd/bridge_design/gec/documents/MTDS20- 10%209%2024%2012.pdf Caltrans, 2013, Memo to Designers 20-8, Analysis of Bridges that Cross Faults; http://www.dot.ca.gov/hq/esc/techpubs/manual/bridgemanuals/bridge-memo-to- designer/page/Section%2020/20-8.pdf Crook, R., Jr., Allen, C.R., Kamb, B., Payne, C.M., and Proctor, R.J., 1987, Quaternary Geology and Seismic Hazard of the Sierra Madre and Associated Faults, western , in Recent Reverse Faulting in the Transverse Ranges, California, U.S. Geological Survey Professional Paper 1339, p. 27-63 Dawson, T., and Weldon, R., 2012, UCERF3 Appendix B: Geologic Slip Rate Data and Geologic Deformation Model (July 9, 2012 draft): http://wgcep.org/sites/wgcep.org/files/AppendixB_GeologicDeformationModel_2012070 9.pdf Jones, L.M., Sieh, K.E., Hauksson, E., and Hutton, L.K., 1990, The 3 December 1988 Pasadena, California Earthquake—Evidence for strike-slip motion on the Raymond fault: Bulletin of the Seismological Society of America, v. 80, p. 474-482. Petersen, M.D., Dawson, T.E., Chen, R., Cao, T., Wills, C.J., Schwartz, D.P, and Frankel, A.D., 2011, Fault Displacement Hazard for Strike-slip Faults, Bulletin of the Seismological Society of America, vol. 101, no. 2, p 805-825. Petersen, M. D. and Wesnousky, S.G., 1994, Fault slip rates and Earthquake Histories for active faults in , Bulletin of the Seismological Society of America, Vol. 84, No. 5, pp. 1608-1649. Treiman, J. Jerome, compiler, 2000, Fault number 103, Raymond fault, in Quaternary fault and fold database of the United States: U.S. Geological Survey website, http://earthquakes.usgs.gov/hazards/qfaults, accessed 08/15/2014 11:52 AM. State of California, 1977, State of California Special Studies Zones, Los Angeles Quadrangle, Official Map, 1:24,000. US Geological Survey, 2010, Quaternary Faults in Google Earth: http://earthquake.usgs.gov/hazards/qfaults/google.php “Provide a safe, sustainable, integrated and efficient transportation system to enhance California’s economy and livability”

MR. TOM OSTROM October 21, 2014 Page 6

US Geological Survey, 2008, National Seismic Hazard Maps – Fault Parameters, http://geohazards.usgs.gov/cfusion/hazfaults_search/hf_search_main.cfm US Geological Survey, 1953, 7.5’ Topographic Map, Los Angeles Quadrangle, scale 1:24,000. Weaver, K.D., and Dolan, J.F., 2000, Paleoseismology and Geomorphology of the Raymond fault, Los Angeles, County, California, Bulletin of the Seismological Society of America, v. 90, p. 1409-1429 Wells, D., and Coppersmith, K., 1994, New Empirical Relationships Among Magnitude, Rupture Length, Rupture Width, Rupture Area, and Surface Displacement, Bulletin of the Seismological Society of America, vol. 84, No. 4, p. 974-1002.

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N

State Route 110

Arroyo Seco Fremont Ave. OC 53-0438 Ave. Fremont Fremont Ave. UP 53-0439 UP Ave. Fremont OC 53-0440 Ave. Fair Oaks Meridian Ave. OC 53-0437 Ave. Meridian Prospect Ave. OC 53-0436 Ave. Prospect Orange Grove Ave. OC 53-0435 Ave. Orange Grove Grand Avenue OC 53-0434 Avenue Grand

Original Map 1:24,000 NOT TO SCALE Figure 1 Location Map 07-LA-110 PM 30.43-31.17 EFIS 000001016 October 2014 Raymond Fault

State Route 110

N Fremont Ave. OC 53-0438 Ave. Fremont Fremont Ave. UP 53-0439 UP Ave. Fremont Fair Oaks Ave. OC 53-0440 Ave. Fair Oaks Meridian Ave. OC 53-0437 Ave. Meridian Prospect Ave. OC 53-0436 Ave. Prospect Grand Avenue OC 53-0434 Avenue Grand Orange Grove Ave. OC 53-0435 Ave. Orange Grove

Original Map 1:24,000 NOT TO SCALE

Source: State of California, 1977, State of California Special Studies Zones, Los Angeles Quadrangle, Official Map, 1:24,000.

Figure 2 Alquist-Priolo Map 07-LA-110 PM 30.43-31.17 EFIS 000001016 October 2014 Raymond fault plotted on 1939 aerial photograph during the construction of State Route 110. Figure from Bryant (1978). View is to the east. Figure 3 1939 Air Photo 07-LA-110 PM 30.43-31.17 EFIS 000001016 October 2014 Raymond Hill N

Fault Scarp

State Route 110

Offset Stream Fremont Ave. OC 53-0438 Ave. Fremont Fremont Ave. UP 53-0439 UP Ave. Fremont Fair Oaks Ave. OC 53-0440 Ave. Fair Oaks Meridian Ave. OC 53-0437 Ave. Meridian Prospect Ave. OC 53-0436 Ave. Prospect Grand Avenue OC 53-0434 Avenue Grand Orange Grove Ave. OC 53-0435 Ave. Orange Grove

Original Map 1:24,000 NOT TO SCALE

Source: United States Geological Survey, 1953, Los Angeles Quadrangle, 1:24,000 Contour interval: 5 feet and 20 feet Figure 4 1953 Topographic Map 07-LA-110 PM 30.43-31.17 EFIS 000001016 October 2014 0.6

0.5

0.4 Main Trace 0.3

Combined 0.2 Fault Displacement (m) Displacement Fault

0.1

0 -200 -100 0 100 200 300 400

Distance from bridge (m)

Graph showing deterministic offset within the bridge footprint. Offset at the bridge (distance = 0) could be up to 0.18 meters.

Figure 5 Deterministic Offset 07-LA-110 PM 30.43-31.17 Bridge 53-0434 EFIS 000001016 October 2014 0.6

0.5

0.4 Main Trace 0.3

Combined 0.2 Fault Displacement (m) Displacement Fault

0.1

0 -200 -100 0 100 200 300 400

Distance from bridge (m)

Graph showing probabilistic offset within the bridge footprint. Offset at the bridge (distance = 0) could be up to 0.2 meters.

Figure 6 Probabilistic Offset 07-LA-110 PM 30.43-31.17 Bridge 53-0434 EFIS 000001016 October 2014