A06_Dwgs-Specs_Anacapa_Rock_Engineering_Report_Final,_01-13-2017.pdf

Prepared for

The U.S. Department of the Interior

NATIONAL PARK SERVICE

Denver Service Center

12795 W. Alameda Parkway, Lakewood CO 80225 (IDIQ No. P15PC00019-Task Order No.: P16PD)

ROCK INVESTIGATION AND ENGINEERING REPORT FOR

THE PROPOSED TWO-CRANE SYSTEM

CHANNEL ISLANDS NATIONAL PARK (CHIS – 185164), CA

(Replacement for the Anacapa Stiff-Leg Derrick Crane)

Prepared by:

412 Mt. Kemble Avenue

PO Box 1946 Morristown, New Jersey 07962-1946

January 2017 https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=imgres&cd=&cad=rja&uact=8&ved=0ahUKEwiD4PbMl5zRAhWGSSYKHbjYBlYQjRwIBw&url=https%3A%2F%2Fcommons.wikimedia.org%2Fwiki%2FFile%3AUS-NationalParkService-Logo.svg&psig=AFQjCNGXe7VXxBUJ5qhjIHZFKjMLx4rywQ&ust=1483196481899994

Rock Engineering Report, Anacapa Island

Channel Islands National Park, California

National Park Service

SEALS PAGE

Name: Rock Investigation and Engineering Report for the Proposed Two-Crane

System, Channel Islands National Park (CHIS-185164) Location: Channel Islands, California Dated: January 2017 Prepared for: The U.S. Department of the Interior, National Park Service Prepared by: Louis Berger

GEOTECHNICAL ENGINEER

Dincer Egin, PhD, PE Louis Berger

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TABLE OF CONTENTS

1.1 Existing and Proposed Conditions

1.2 Site Setting

2.1 Field Investigation

2.2 Regional Geology of Anacapa Island

2.3 Engineering Geology and Rock Engineering of the Cranes’ Foundation

2.4 Stability of the Rock Masses

3.1 Crane Foundation Support

3.2 Crane Foundation Design Parameters

3.3 Crane Foundation Locations

FIGURES

Figure 1 Site Location Map Figure 2 Rending of a Two-Crane System (copied from structural engineering drawings) Figures 3 to 14 Site Photographic Records

TABLES

Table 1 Estimated rock strength near the foundation area of the upper crane Table 2 Estimated rock strength near the foundation area of the lower crane Table 3 Geotechnical classification of the rock masses surrounding the new crane foundations Table 4 Anacapa Cranes, Estimated Resistance of 10 feet long, 20 inches diameter Single Rock Anchor .. 7 Table 5 Anacapa Cranes Alternative Foundation Anchor Capacities

APPENDICES

Appendix 1 Geotechnical strength, capacity, deflection analysis

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EXECUTIVE SUMMARY

The United States Department of the Interior, National Park Service (NPS), requested that Louis Berger and Moffatt & Nichol Engineers execute design services for pre-design and a schematic design document to replace the Anacapa stiff-leg derrick crane with a two-crane system in Channel Islands National Park, California, in accordance with the terms and conditions of the indefinite delivery/indefinite quantity (IDIQ) contract. Figure 1 shows the project site. The crane site is located on Anacapa Island, Channel Islands, Ventura County, California, immediately east of the island on what is referred to as “East Anacapa Island, Landing Cove.” The Landing Cove is about 12 miles off the coast of Ventura Harbor in California (Figure 1). Based on a value analysis workshop conducted in 2011, a two-crane system, with one crane on the upper landing and the other on the lower landing, was selected.

This report evaluated the surface, subsurface conditions, rock characteristics, including rock type and pertinent rock strength, hardness and rock stability at each proposed crane locations and also recommended crane foundation design data, alternative crane locations from rock engineering perspective, as well as provided rock strength parameters that can be used in the design analysis. This investigation consisted of conducting rock engineering study that volcanic rocks, mostly of andesite exposed almost exclusively within and close to the proposed crane foundation area. In situ rock strength estimates were made using a Schmidt hammer and correlating the field data into uniaxial compressive strength. Rock quality designation (RQD) (in %) was estimated based on visual observations and industry-accepted formulations.

Anacapa Island is predominantly volcanic in origin, composed mainly of highly weathered Miocene (between 19 and 15 million years ago) volcanic rock that has been eroded mainly by atmospheric agents, wind, and waves. The presence of pillow lava and a vesicular surface are evidence that much of the volcanic action took place underwater. The rocks exposed within the area surrounding the crane locations are relatively uniform; homogeneous; and generally consist of dark gray to brown to black, fine- to medium-grained, frequently jointed in 3-5 directions, moderately weathered in general, and highly weathered in the upper (i.e., outer) 10 feet, generally vesicular andesite-basalt. The rock mass is jointed in four main directions and has irregular secondary jointing. The rock strength was estimated, and the results are given in Table 1 and Table 2. Based on geotechnical classification of the rock masses surrounding the new crane foundations, rock mass rating (RMR) ranged between 32 and 37, both of which point to Class IV-Poor Rock characteristics.

The state of the discontinuity planes in terms of geometry, spacing, aperture, filling, and other characteristics was evaluated during this investigation, and no major failing potential was identified, except for localized rock falls. Measures mitigating rock fall are given in Section 2.3 of this report.

Using data obtained from this investigation, and the cranes’ data, a preliminary foundation anchor geometry is estimated that 20 inches diameter 10 feet long single anchor can resists 25 tons uplift forces with negligible lateral displacements. Once the load and load combinations are refined, it is possible to evaluate if to reduce the anchor diameters and increase the number of anchors, or have a single anchor to resist crane loads. As an example, 10 feet long, 6 and 8 inches diameter, each with a 1-inch high-strength steel core (Fy=70 ksi), ground anchors can resist an allowable uplift force of 9 tons, and 8.5 tons per anchor, respectively. An anchor with a central, single, steel core, however, cannot resist significant lateral loads and overturning moments as such to be developed from each crane both in static and operating conditions. To allow anchors to resist lateral loads/overturning moments, the anchor would need to be fully cased using a minimum ½-inch wall thickness steel casing

National Park Service Page iii pipe (Fy=36ksi) until where bending moments, shear forces and lateral movements would be negligible. In Section 3.2 of this report, crane foundation design parameters are recommended.

Alternative crane locations and elevations also were proposed from a more favorable rock mass perspective.

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1.0 INTRODUCTION

The United States Department of the Interior, National Park Service (NPS) requested that Louis Berger and Moffatt & Nichol Engineers execute design services for pre-design, and schematic design document to replace the Anacapa Stiff-Leg Derrick Crane with a Two-Crane System in Channel Islands National Park, California, in accordance with the terms and conditions of the indefinite delivery/indefinite quantity (IDIQ) contract. The project site is shown in Figure 1.

This report evaluates the surface and subsurface conditions and identifies surface and subsurface rock characteristics, including rock type and pertinent rock strength, hardness, and rock stability, at each proposed crane location, and within the vicinity of the crane load influence zone. The report also includes recommendations for the proposed crane foundations, alternative crane locations from a rock engineering perspective, and provides rock strength parameters that can be used in the design analysis.

1.1 Existing and Proposed Conditions

The crane system is required to transport equipment and materials from the vessel to the lower dock, then from the lower dock to the top of the island in a bluff with a 100-foot vertical lift (Figure 2).

Anacapa Island does not have fresh water source, which is essential for employees and volunteers that perform multi-day tours as well as for watering nursery plants and native planting that are being used to revegetate the island to a natural state. The limited water supply restricts the number of employees and volunteers that stay on the island and requires employees and volunteers to carry heavy 5-gallon jugs of water up the stairs (Figure 3). Lack of water also limits the natural resources revegetation and cultural resource preservation. Without the crane, water must be pumped from a water barge (in dangerous open water conditions) up to the top of the island.

This project will replace an 80-year-old, non-functioning, obsolete, stiff-leg derrick crane located on Anacapa Island with an alternative unloading/loading crane facility. The existing crane rests on a concrete pad that sits on top of the volcanic rock, and the 3-guy rods anchored into rock support the mast.

In 2011, the NPS conducted a value analysis work shop and discussed six main alternatives and several subalternatives. The value analysis workshop also developed a seventh alternative, which was chosen by advantage. Accordingly, the proposed replacement is a two-crane system, with one crane on the upper landing and the other on the lower landing. Figure 2 shows a rendering of the proposed two-crane system. The two-crane system will include contemporary safety and efficiency features such as cable stops, a live boom, and geared or hydraulic swing mechanisms in a closed case. The system will improve visual controls of the load lift, allowing a quick pick from the ship to the lower dock, and then a second lift from the lower dock to the top of the island. This maneuverability is essential for a safe, reliable operation with surging tides and heavy wave action in the open ocean setting.

From a constructability perspective, the dock and crane location and configuration at the Anacapa Island Landing Cove will make construction access difficult. Equipment will be lifted to the site by a heavy lift helicopter. After the new concrete is placed and the new crane is assembled, the old crane and concrete rubble will be removed from the site. The old crane and concrete rubble will be recycled on the mainland.

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1.2 Site Setting

The crane site is located in Anacapa Island, Channel Islands, Ventura County, California, immediately east of the island on what is referred to as “East Anacapa Island, Landing Cove.” The Landing Cove is about 12 miles off the coast of Ventura Harbor in California. East Anacapa Island is off limits for human settlement but has several NPS buildings, a light house, a former US Coast Guard water storage building, and a heliport that is connected to a concrete rain water collection pan (see Figure 1).

West Anacapa is the largest and highest islet, rising to an altitude of 930 feet at Vela Peak (Summit Peak). East and Middle Anacapa have fairly level areas at their tops. Middle Anacapa Island reaches an altitude of 325 feet, and East Anacapa Island is 250 feet at its highest point. All three islands total 699 acres, or about 1.1 square miles.

The proposed two new cranes will be installed on East Anacapa Island. The Dulin & Boynton 2011 survey gives an average elevation of El. +10 feet for the wooden landing platform, El. +20.5 feet for the lower crane platform area, and El. + 104.7 feet for the upper crane platform. Maximum site elevation within the immediate vicinity of the crane area (upper crane) is El. +135 feet (Vertical Datum is NGVD1929, and requires an addition of 2.42 feet to convert it to NAVD88).

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2.0 ROCK INVESTIGATION AND TESTING

2.1 Field Investigation

This subsurface investigation consisted of conducting rock engineering study that volcanic rocks, mostly of andesite exposed almost exclusively within and close to the proposed crane foundation area (see Figure 3 and 4). Rock were described in line with the ASTM D 5434, Standard Guide for Field Logging of Subsurface Explorations of Soil and Rock, and the CALTRANS Foundation Manual, Appendix A Soil and Rock Logging Classification and Presentation Manual (2012). Evaluations included rock quality, the state and geometry of the discontinuities, rock strength, rock mass characteristics in line with the guidelines set in ASTM D 5878: Standard Guides for Using Rock-Mass Classification Systems for Engineering Purposes. Rock investigation and engineering was performed by Dr. D. Egin, PhD, PE of Louis Berger. In situ rock strength estimates were made using a Schmidt hammer and correlating the field data into uniaxial compressive strength developed by Deere and Miller (Engineering Classification and Rock Strength Properties for Intact Rock, Air Force Weapons Laboratory, Technical Report, No. AFNL-TR65-116, New Mexico, 1966).

Rock mass strength was estimated for each crane foundation bedrock using the guidelines set in AASHTO Load-and-Resistance Factor Design Bridge Design Specifications (2012).

RQD (in %) was estimated using the commonly accepted formula of RQD (%) = 110.4-3.68 Jn where Jn is the number of joints per linear meter.

2.2 Regional Geology of Anacapa Island

Anacapa Island, along with the other Northern Channel Islands, represents a seaward extension of the Santa Monica Mountains. Anacapa was formed by volcanic eruptions between 19 and 15 million years ago (Miocene geologic age). These eruptions are believed to have been caused by thinning of ocean crust as the block containing the northern Channel Islands and Santa Monica mountains was rotated clockwise by the transverse motion of the Pacific and North American plates. The presence of pillow lava and vesicular surface are evidence that much of the volcanic action took place underwater. Anacapa Island is predominantly volcanic in origin, composed mainly of highly weathered Miocene volcanic rock that has been eroded mainly by atmospheric agents, wind, and waves. The rocks that make up Anacapa are composed of lava, breccia, volcanic ash, and cinders.

Vesicles (Figure 5), fissures forming sea caves and blowholes, are common.

Approximately 40-feet-high Arch Rock (Figure 6), the easternmost extension of Anacapa Island, is a natural bridge formed by sea erosion. Erosion has heavily weathered the lava formations of Anacapa, and wave action caused the island to split into three islets in recent prehistoric times (Figure 7). The islets display a wide variety of erosional features including sea arches, sea caves, stacks, wave-cut platforms, surge channels, and blowholes.

2.3 Engineering Geology and Rock Engineering of the Cranes’ Foundation

The rocks exposed within the area surrounding the crane locations are relatively uniform, homogeneous, and generally consist of dark gray to brown to black, fine- to medium-grained, frequently jointed in 3-5 directions, moderately weathered in general, and highly weathered in the upper (i.e., outer) 10 feet, generally vesicular andesite-basalt (Figures 3, 4, 5, 8, and 9). The rock mass is jointed in four main directions and demonstrates irregular secondary jointing as follows:

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1. Joint set 1: 4 inches, tight, and smooth: N05E/8NW

2. Joint set 2: 2-8 inches spacing, tight, and rough: E-W/85S

3. Joint set 3: 6 inches spacing, tight, and rough: N30E/85SE

4. Joint set 4: 6 inches spacing, open to tight, smooth: N55E/55SE

The rock strength was estimated using a Schmidt hammer. Estimated Schmidt hardness and rock strength for different orientation of the hammer is tabulated below for the lower crane and upper crane foundation area, separately:

Table 1: Estimated rock strength near the foundation area of the upper crane

Measured Schmidt Hardness (unit)

27 31 35 20 20

Orientation (against rock face) → ↓ → → → ↓

Uniaxial Compressive Strength (MPa)

28 40 42 50 23 28

Uniaxial Compressive Strength (psi)

4,061 5,801 6,091 7,251 3,335 4,361

As summarized in Table 1, the estimated rock strengths are highly variable depending on the degree of weathering. Because the tests are conducted on relatively smooth and hard rock surfaces, high strength values are considered biased sampling and should not be used in the design analysis.

Rock strength for the area surrounding the lower crane is also summarized below, according to which lower crane bedrock has somewhat lower strength values than the upper crane bedrock. This phenomenon is explained by the constant exposure of the lower crane area to ocean atmospheric conditions and the splash zone.

Table 2: Estimated rock strength near the foundation area of the lower crane

Measured Schmidt Hardness (unit)

10 22 12 25 8 35

Orientation (against rock face)

Uniaxial Compressive Strength (MPa)

18 18 25 20 30 18 42

Uniaxial Compressive Strength (psi)

2,610 2,610 6,091 2,900 3,625 2,610 6,091

Considering that the number of joints (and cracks) per linear meter (about 3.3 feet) is about 25, the estimated RQD values are less than 20%. Rock face observations showed the andesite does not ring when struck with a hammer (Figure 9); usually breaks softly (i.e., does not cause chips to fly); and breaks with round weathered fractures. Cracks are also weathered to generally moderately and are generally closed (tight); the spacing is usually greater than 12 inches. This description, as summarized below, qualifies the bedrock that will support the new cranes as Class IV, “Poor Rock” according to the AASHTO (2012).

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Table 3: Geotechnical classification of the rock masses surrounding the new crane foundations (which has been attempted using the classification provided in AASHTO (2012), tables 10.4.6.4.1, 10.4.6.4.2, and 10.4.6.4.3)

Parameter Strength of Intact

Rock

RQD

Spacing of joints

Condition of joints

Ground-water conditions

Adjustment Factor

Rock Mass

Rating

(RMR)

RMR

Description

Relative rating for the Upper Crane

(3,611- 7,500 psi)

(20)

(2 in.- 12 in.)

12 10 -7 32 IV-Poor Rock

Relative rating for the Lower Crane

(3,611- 7,500 psi)

(20)

(2 in.- 12 in

20 7 -7 37 IV-Poor Rock

2.4 Stability of the Rock Masses

The rock masses exposed within the proposed crane foundation areas are relatively uniform, well jointed, moderately weathered, andesitic pillow lava rocks. The stability of the rock masses is mainly governed by the state and orientation of the discontinuities. The discontinuity planes were evaluated in terms of geometry, spacing, aperture, filling and other characteristics during this investigation. The major discontinuity planes mainly as joints, and to a lesser extent cracked zones, were collected and statistically generalized and given in Section 2.3, above. For operational and safety of the new cranes, rock stability with respect to the following potential failure modes was assessed:

• Wedge Failure

• Circular Failure

• Plane Failure

• Toppling(flexural) Failure

Wedge failure commonly involves a rock-slope failure in which the structural features (i.e., mainly planes defined by the discontinuities) intersect such that sliding can occur along the line of intersection of two or more such planes. Large-scale, intersecting planes that would cause a large-scale wedge failure were not identified within or close to the crane foundation areas.

Circular failure is where the bedrock becomes highly weathered and disintegrated and individual particles are very small as compared with the size of the slope. When these particles are not interlocked as a result of their shape, water content, or other factors, a potential for a circular failure exists. The andesitic rock masses surrounding both potential crane locations do not present major crushed or disintegrated rock behavior, thus, eliminating the potential for a circular failure.

Plane failure generally is rare in rock slopes because it is only occasionally that all the geometrical conditions required to produce such a failure occur in an actual slope. Potential slope instability for a plane failure does not exist within or close to the crane foundation area, but may take place in an area in the long run, as shown in Figure 13.

Toppling (flexure) failure also was reviewed. A lack of continuous columnar jointing, combined with the field engineering geological data, rules out a potential for flexural toppling, block toppling, or block

National Park Service Page 6 flexure toppling. However, a number of possible secondary toppling in the form of rock fall would develop once the shear strength of the bedrock is exceed by an external stress (heavy rain, earthquake, etc.). Examples of a potential rock fall mass are shown in Figure 14, and noted on the roof of the cabin located at the lower landing area (i.e., also lower crane area). Generally accepted approaches to the rock fall problems are 1) restraining rocks from falling, b) mitigating measures to dissipate the energy that has been acquired by falling rock, and c) providing a ditch (i.e., catchment area) at the foot of the slope. Of these measures, the dissipation of energy of the falling rock acts as a passive measure, and among other measures draping nets and chain-link mesh and check fences along the slope could be effectively applied to protect the lower crane and visitors. The objective of installation of the draping net is to decelerate falling rock and retard its angular velocity, thus preventing rocks from building up momentum, reducing fall velocities and bounce heights, and to guide falling rock into the toe slope, or a collection area.

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3.0 FOUNDATION EVALUATIONS

3.1 Crane Foundation Support

Both of the proposed cranes will rest on, and be anchored into, andesite bedrock, which is described generally as having ‘poor rock” characteristics. In addition, currently selected crane elevations and locations indicate bedrock about 3 to 8 feet below the crane pedestal footing elevation of the upper crane (Figures 10 and 11) and about 2 feet below the pedestal column of the lower crane (Figure 4).

Crane loads and reactions are not yet known. However, the stability of both cranes is controlled by the lateral loads, large overturning moments, and uplift forces when loaded. Crane loads are to be transferred to, and reactions to be derived from, the andesitic bedrock, the characteristics of which are described above. In line with the guidelines given in AASHTO 2012, the shear strength of the rock masses where the crane reactions will be derived from is estimated to be 20 pounds per square inch (psi) for both upper and lower crane foundation areas (Appendix 1).

Using data obtained from this investigation, and the cranes data given in the Scope and Cost Validation Report (2011), a preliminary foundation anchor geometry was estimated, and it is provided in Appendix 1. It is estimated that a 20 inches diameter 10 feet long single anchor can resist the following magnitude of crane loads with controlled deflection with factored (factor of safety) as tabulated below (see also Appendix 1):

Table 4: Anacapa Cranes, Estimated Resistance of 10 feet long, 20 inches diameter Single Rock Anchor

Loads/Forces Upper Crane Lower Crane

Uplift Resistance (factored, tons) 25 25

Compressive Resistance (factored, tons) 27 27

Maximum Deflection (in) 0.078 0.024

Maximum bending Moment (in-kips) 11,500 5,750

Maximum Shear (kips) -460 kips @2.0 ft. -270 kips @1.8 ft.

Maximum Settlement (in) <0.01 <0.01

Because the rock may be buried below concrete, it is important that the anchor foundation be installed a full 10 feet into andesite and that the space between the top of the rock and the bottom of the crane pedestal be filled with at least 4,000 psi dense packing concrete. The packing concrete must be poured on to cleaned, but “rough,” bedrock surface, and must be properly cured for at least 7 days before placing the crane pedestal and the cranes.

This estimate is preliminary, and, once the project structural engineer determines loads acting at the base of the crane pedestal, foundation anchor, or anchors that will support each crane, the final design will be developed. The loads acting at the base of the crane in terms of horizontal load, vertical load, and overturning moment loads should include loads or load combinations of dead load, live load, wind load, and earthquake load. Once the load and load combinations are refined, it will be possible to evaluate if the anchor diameters can be reduced or if the number of anchors can be increased, or if a single anchor would resist crane loads. As an example, 10 feet long, 6 and 8 inches diameter, each

National Park Service Page 8 with a 1-inch high strength steel core (Fy=70 ksi) ground anchors can resist an allowable uplift forces of 9 tons, and 8.5 tons per anchor, respectively ( Table 5 and Appendix 1). An anchor with a central, single, steel core, however, cannot resist significant lateral loads and overturning moments as such to be developed from each crane both in static and operating conditions. To allow anchors to resist lateral loads/overturning moments, the anchor would have to be fully cased using a minimum ½-inch wall thickness steel casing pipe (Fy=36ksi) until the point where bending moments, shear forces, and lateral movements would be negligible.

Table 5: Anacapa Cranes Alternative Foundation Anchor Capacities

Anchor Diameter (inches) 6 8

Anchor Length (feet) 10 7

½-inch wall thickness casing length (feet)

10 7

Central core diameter ( inches) 1 1

Uplift Resistance (factored/allowable, tons)

9 8.5

Estimated Deflection (inches) <0.1 <0.1

3.2 Crane Foundation Design Parameters

For design of the foundation anchors, the following design parameters can be used:

• Allowable bearing pressure (vertical): 12 tsf (tons per square foot),

• Lateral bearing pressure 1,000 psf/ft.,

• Ultimate Unit Bond Stress: 20 psi

• Ultimate friction factor (between concrete/grout foundation and clean andesite): 0.60,

• Seismic Site Class B (Mapped Spectral Response Accelerations at Short Periods, Ss and at 1-second Periods, S1); Fa=Fv=1.0).

3.3 Crane Foundation Locations

Currently selected locations for the cranes are close to the edge of the bluff, a steep rock face, where rock is weathered and jointed.

3.3.1 Upper Crane Location: The proposed location of the new crane is about 15 feet north of the existing stiff leg derrick crane location and about 6 feet west of the edge of the existing retaining wall.

The existing retaining wall and the concrete platform above are in poor condition (Figure 11) and should not be relied upon for their load bearing ability and strength for the new crane foundation. It is probable that the upper crane elevation (approximate El. +104.7 feet) may be as much as 3-8 feet above bedrock, which would require mass packing concrete and likely a new retaining wall to resist large lateral loads and overturning moment (lateral loads and large moments of the existing stiff leg crane is resisted buy three guy musts). The retaining wall would also need to be anchored back to rock mass to control lateral movements. Both the retaining wall construction and the tie-back anchors would present constructability issues because the toe of the current (and future) retaining wall is within a few feet of the steep free rock mass.

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If the edge of the foundation elements (i.e. anchor, or anchors) is kept at a distance of 15 feet from the edge of the existing retaining wall at elevation +104.7 feet, the rock would be at a shallower depth than 3-8 feet, and the need for a retaining wall would likely be eliminated.

If the proposed location of the crane is to be maintained, alternatively, the pedestal elevation could be dropped down to top of the bedrock (probably El. +100 feet); therefore, the need for a retaining wall is eliminated. A foundation anchor, or anchors, could be installed directly into bedrock, which would provide adequate burden (i.e., distance to the edge of the bluff) to resist lateral loads.

3.3.2. Lower Crane Location: The new lower crane is proposed to be located at approximate elevation El. +20.2 feet about 3 feet north from the edge of the existing concrete landing platform (Figure 4).

At this location, the top of the rock appears to be about 2 feet below the top of the concrete platform.

The existing concrete is in poor conditions (Figure 4), its load bearing ability is compromised, and it should not be relied on for its load bearing and strength ability for this crane foundation. It is important that the minimum distance from the nearest rock edge must be 33 inches to avoid edge failures, and gradual loss of foundation resistance to lateral/overturning forces. In addition, the existing concrete will need to be removed and replaced with new levelling/packing concrete if the pedestal bottom elevation is to be maintained at El. +20.2 feet. The foundation design and construction documents should include details for effective load transfer between the bedrock and the packing concrete, unless the pedestal bottom elevation is dropped down to the top of the bedrock elevation (approximately El. +18 feet).

The burden (i.e., distance to the nearest free rock face) is about 3 feet and is marginal: the crane foundation will transfer lateral loads and large overturning moments to andesitic bedrock, the integrity of the rock mass is maintained by the state (rough, smooth, etc.,) and interlocking of the well-developed joints and cracks. For long-term satisfactory foundation performance and to prevent joints being dislodged during periodic loading and unloading operations, a retaining structure should be constructed and anchored to the rock-side. Because of limited site access and also work space (for conventional wall form props, etc.), such a retaining structure could be built rapidly by 6-8 in. thick reinforced shotcrete. The purpose of such a structure is not to retain soil/rock/surcharge pressures but rather to maintain the integrity of the rock mass and reduce its exposure to harsh atmospheric conditions.

Because of these constructability issues, the need to maintain the integrity of the rock mass by a retaining structure, and the crane will take up part of the limited useable space, two alternative lower crane locations should be evaluated. Both locations would not require lengthy foundation preparations or a new retaining structure and would not take up the useful public space.

The first recommended location is at the approximate elevation of El. +36 feet and is shown in Figure

12. At this location, the bedrock would need to be trimmed, and its surface levelled to receive foundation anchors and plate. No retaining structure would be required because the nearest anchor to free face would be at least 5 feet, and the rock at the free face slopes. This location also provides easy constructability from a marine platform because it would require drilling and grout for anchors and small amounts of concrete for levelling. The disadvantages include access for maintenance (unless stairs are built), and a longer boom length.

The second recommended location is immediately behind the retaining wall at the approximate elevation of El. +22 feet and is shown in Figure 12. At this location, there is a large platform to accommodate a new crane where the bedrock would need to be trimmed, and its surface levelled to receive foundation anchors and plate. No retaining structure would be required because the nearest

National Park Service Page 10 anchor to free face would be at least 5 feet, and the rock at the free face slopes. This location also provides easy constructability from a marine platform because it would require drilling and grout for anchors and small amounts of concrete for levelling. Immediately behind the retaining wall, added steps, or cutting part of the retaining wall, would provide access for service and maintenance. The disadvantages include a longer boom length, and protection against seawater as it within the splash zone.

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4.0 CONCLUSIONS AND RECOMMENDATIONS

1. This report evaluated the surface and subsurface conditions and rock characteristics, including rock type and pertinent rock strength, hardness, and rock stability, at each proposed crane location.

It also recommended crane foundation design data and alternative crane locations from a rock engineering perspective and provided rock strength parameters that can be used in the design analysis.

2. The site of the cranes is Anacapa Island, Channel Islands, Ventura County, California, immediately east of the island that is referred to as “East Anacapa Island, Landing Cove.” The Landing Cove is about 12 miles off the coast of Ventura Harbor in California. Based on a value analysis workshop conducted in 2011, a two-crane system, with one crane on the upper landing and the other on the lower landing, was selected. From a constructability perspective, the dock and crane location and configuration at the Anacapa Island Landing Cove would make construction access difficult.

Equipment will be lifted to the site by a heavy lift helicopter. After the new concrete and the new crane is assembled, the old crane and concrete rubble will be removed from the site. The old crane and concrete rubble will be recycled on the mainland.

3. This subsurface investigation consisted of a rock engineering study of the volcanic rocks, mostly of andesite, exposed almost exclusively within and close to the proposed crane foundation area.

In situ rock strength estimates were made using a Schmidt hammer and correlating the field data into uniaxial compressive strength. RQD (in %) was estimated based on visual observations and industry-accepted formulations.

4. Anacapa Island was formed by volcanic eruptions between 19 and 15 million years ago (Miocene geologic age). The presence of pillow lava and vesicular surface provide evidence that much of the volcanic action took place underwater. Anacapa Island is predominantly volcanic in origin, composed mainly of highly weathered Miocene volcanic rock that has been eroded mainly by atmospheric agents, wind, and waves. The rocks exposed within the area surrounding the crane locations are relatively uniform and homogeneous and generally consist of dark gray to brown to black, fine- to medium-grained, frequently jointed in 3-5 directions, moderately weathered in general, and highly weathered in the upper (i.e., outer) 10 feet, generally vesicular andesite-basalt The rock mass is jointed in four main directions and demonstrates irregular secondary jointing.

The rock strength was estimated and the results are given in Table 1 and Table 2. Based on a geotechnical classification of the rock masses surrounding the new crane foundations, RMR ranged between 32 and 37, both of which point to “Class IV-Poor Rock” characteristics.

5. The discontinuity planes were evaluated during this investigation, in terms of geometry, spacing, aperture, filling, and other characteristics, and no major failing potential was identified, except for localized rock falls. Measures mitigating rock fall are given in Section 2.3 of this report.

6. Using data obtained from this investigation, and the cranes’ data, it is estimated that a single anchor foundation of 20 inches diameter and 10 feet long can resist 25 tons of uplift forces with negligible lateral displacement. Once the load and load combinations are refined, it will be possible to evaluate reducing the anchor diameters and increasing the number of anchors. As an example, 10 feet long, 6 and 8 inches diameter, each with a 1-inch high-strength steel core (Fy=70 ksi) ground anchors can resist an allowable uplift forces of 9 tons, and 8.5 tons per anchor, respectively. An

National Park Service Page 12 anchor with a central, single, steel core, however, cannot resist significant lateral loads and overturning moments as such from each crane both in static and operating conditions. To allow anchors to resist lateral loads/overturning moments, the anchor would have to be fully cased using a minimum ½-inch wall thickness steel casing pipe (Fy=36ksi) until it could be determined that bending moments, shear forces, and lateral movements would be negligible.

7. In Section 3.2 of this report, crane foundation design parameters were recommended. Alternative crane locations and elevations that were more favorable from a rock mass perspective also were identified.

National Park Service Page 13

5.0 STATEMENT OF LIMITATIONS

The data presented and the opinions expressed in this report are qualified as follows:

1. This report has been prepared by Louis Berger for the NPS to be used solely by the NPS in the evaluation and performance of the proposed two-crane system at Channel Islands National Park, California. The report has not been prepared for use by other parties and may not necessarily contain sufficient information for the purposes of other parties or other uses. Any undisclosed and/or unpermitted alternative use shall be at that party’s own risk and without liability to Louis Berger.

2. The evaluations and recommendations provided in this report are based upon our understanding of the described project information and on our interpretation of the information, the visible conditions for accessible properties and the data which were available and/or collected during the performance of this study. Unless otherwise stated, the work performed by Louis Berger should be understood to be exploratory and interpretational in character. Any results, findings, or recommendations contained in this report may be the result, at least in part, of professional judgment and not necessarily based solely on pure science and engineering.

3. Our professional geotechnical engineering services for this project have been performed using a degree of care and skill ordinarily exercised, under similar circumstances, by reputable geotechnical consultants practicing in this or similar localities. No other warranty, expressed or implied, is made as to the professional advice in this report.

4. In preparing this report, Louis Berger has relied upon and presumed accurate certain information (or the absence thereof) about the site and adjacent properties provided by governmental officials and agencies, the Client, other consultants, and others identified herein.

Except as otherwise stated, Louis Berger has not attempted to verify the accuracy or completeness of any such information. Louis Berger derived the data in this report primarily from visual inspections, examination of records in the public domain, and a limited number of boreholes and tests where we were granted access. The passage of time, manifestation of latent conditions, or occurrence of future events may require further exploration at the site, analysis of the data, and reevaluation of the findings, observations, and conclusions expressed in the report.

5. No warranty or guarantee, whether express or implied, is made with respect to the data reported or findings, observations, and conclusions expressed in this report. Further, such data, findings, observations, and conclusions are based solely upon site conditions in existence at the time of investigation.

6. The data reported and the findings, observations, and conclusions expressed in the report are limited by the scope of services, including the extent of subsurface exploration and other tests.

The scope of services was defined by the requests of the Client, the time and budgetary constraints imposed by the Client, and the availability of access to the site. This report has been prepared on behalf of and for the exclusive use of the Client, and is subject to and issued in connection with the Agreement and the provisions thereof.

National Park Service Page 14

6.0 REFERENCES

AASHTO LRFD Bridge Design Specifications (2012).

ASTM D 5434 Standard Guide for Field Logging of Subsurface Explorations of Soil and Rock.

ASTM D 5878: Standard Guides for Using Rock-Mass Classification Systems for Engineering

Purposes.

CALTRANS (2012) Foundation Manual, Appendix A Soil and Rock Logging Classification and

Presentation Manual.

Deere and Miller (1966) Engineering Classification and Rock Strength Properties for Intact Rock, Air

Force Weapons Laboratory, Technical Report, No. AFNL-TR65-116, New Mexico.

Federal Emergency Management Agency (FEMA), 1997, NEHRP Recommended Provisions for

Seismic Regulations for New Buildings and Other Structures: FEMA 302/303.

International Building Code (IBC), 2016 California edition.

U.S. Geological Survey (USGS), 2002, National Hazard Maps, Conterminous Unites States, revised April 2003.

U.S. Geological Survey (USGS), 2006.

Weigand P. W. (1998), Editor. Contributions to the Geology of the Channel Islands, Southern California, Pacific Section American Association of Petroleum Geologists, Miscellaneous Publication 45, 196 p.

Channel Island National Park, California

National Park Service Page 6-2

FIGURES

miles km

Figure 1: Anacapa Island Site Location Plan (Copied from Google Earth)

Figure 2: Rendering of a two-crane alternative (preferred alternative) copied from structural engineering drawings

Figure 3: A view of the bluff between the lower and upper crane platforms, and general view of the volcanic rocks.

Figure 4: Foundation area and the exposed volcanic rocks at the lower crane area. Red circle show the approximate location for the lower crane.

Figure 5: Vesicular volcanic rock (andesite) and typical pillow lava apparence

Figure 6: Arch Rock formed by sea erosion of Miocene volcanic rocks

Figure 7: Formation of Islets due to sea erosion, West of Anacapa Island

Figure 8: General view of the andesite-basalt rock mass

Figure 9: Heavily jointed andesite

Figure 10: Approximate location (red circle) and elevation for the lower crane (top of the oncrete platform may be 3-8 feet above bedrock, also See figure 11)).

Figure 11: Upper crane platform supported on 8 feet high retaining wall behind which there may be fill supporting the current derrick crane platform.

Figure 12: Lower crane alternative locations

Figure 13: Potential rock fall area by plane failure(s)

Figure 14: Rock pieces to potentially fall (marked in star)

Channel Island National Park, California

National Park Service Page 6-3

APPENDIX 1

CALCULATION SHEETS AND ANCHOR CAPACITY ESTIMATES

0 0.002 0.004 0.006 0.008 0.01 0.012 0.014 0.016 0.018 0.02 0.022 0.024

Case 1 Case 2

LATERAL DEFLECTION (inches)

ANACAPA CRANE (UPPER) LATERAL DEFLECTION

D ep th (f t)

0 0.002 0.004 0.006 0.008 0.01 0.012 0.014 0.016 0.018 0.02 0.022 0.024

Case 1 Case 2

Bending Moment (in-kips)

-1000 -500 0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 5500 6000

Case 1 Case 2

ANACAPA ISLAND, CA, Lower Crane

D ep th (f t)

-1000 -500 0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 5500 60

Shear Force (kips)

-300 -250 -200 -150 -100 -50 0 50 100

Case 1 Case 2

ANACAPA ISLAND,CA LOWER CRANE

D ep th (f t)

-300 -250 -200 -150 -100 -50 0 50 10

-0.01 0 0.01 0.02 0.03 0.04 0.05 0.06 0.07

Case 1 Case 2

Lateral Deflection (inches)

ANACAPA ISLAND, CA, UPPER CRANE

D ep th (f t)

-0.01 0 0.01 0.02 0.03 0.04 0.05 0.06 0.07

Bending Moment (in-kips)

-1000 0 1000 2000 3000 4000 5000 6000 7000 8000 9000 1E4 1.1E4 1.2E4

Case 1 Case 2

ANACAPA ISLAND, CA UPPER CRANE

D ep th (f t)

-1000 0 1000 2000 3000 4000 5000 6000 7000 8000 9000 1E4 1.1E4 1.2

Shear Force (kips)

-500 -450 -400 -350 -300 -250 -200 -150 -100 -50 0 50 100

Case 1 Case 2

ANACAPA ISLAND, CA, UPPER CRANE

D ep th (f t)

-500 -450 -400 -350 -300 -250 -200 -150 -100 -50 0 50 10

Resistance/F.S. (tons)

CRANE FOUNDATION ANCHOR IN UPLIFT (D=20 in; L=10 ft.)

D ep th ft

0 2 4 6 8 10 12 14 16 18 20 22 24 26

0.

1.

2.

3.

4.

5.

6.

7.

8.

9.

Skin Friction

Self-Weight

Total Capacity

Resistance/F.S. (tons)

CRANE FOUNDATION ANCHOR IN UPLIFT (D=20 in; L=10 ft.)

D ep th ft

0 2 4 6 8 10 12 14 16 18 20 22 24 26

0.

1.

2.

3.

4.

5.

6.

7.

8.

9.

Skin Friction

Self-Weight

Total Capacity

Resistance/F.S. (tons)

CRANE FOUNDATION ANCHOR IN COMPRESSION (D=20 in; L=10 ft.)

D ep th ft

0 2 4 6 8 10 12 14 16 18 20 22 24 26

0.

1.

2.

3.

4.

5.

6.

7.

8.

9.

Skin Friction

Tip Resistance

Total Capacity

Resistance/F.S. (tons)

CRANE FOUNDATION ANCHOR IN COMPRESSION (D=20 in; L=10 ft.)

D ep th ft

0 2 4 6 8 10 12 14 16 18 20 22 24 26

0.

1.

2.

3.

4.

5.

6.

7.

8.

9.

Skin Friction

Tip Resistance

Total Capacity

Axial Load (tons)

CRANE ANCHOR SETTLEMENT (D=20 in.; L=10 ft.)

S et tl em en t in

0 20 40 60 80 100 120 140 160 180 200

0.

0.

0.

0.

0.

0.

0.

0.

0.

0.

0.

0.

0.

0.

0.

0.

0.

0.

0.

Dia=0.66 ft

Axial Load (tons)

CRANE ANCHOR SETTLEMENT (D=20 in.; L=10 ft.)

S et tl em en t in

0 20 40 60 80 100 120 140 160 180 200

0.

0.

0.

0.

0.

0.

0.

0.

0.

0.

0.

0.

0.

0.

0.

0.

0.

0.

0.

Dia=0.66 ft

Foundation Anchor.sfo

SHAFT for Windows, Version 2012.7.11

Serial Number : 157283653

VERTICALLY LOADED DRILLED SHAFT ANALYSIS

(c) Copyright ENSOFT, Inc., 1987-2012

All Rights Reserved

Path to file locations : C:\Desk Top Back up\Geotechnical Reports\NPS\Channel Island, CA\Shaft\ Name of input data file : Foundation Anchor.sfd Name of output file : Foundation Anchor.sfo Name of plot output file : Foundation Anchor.sfp Name of runtime file : Foundation Anchor.sfr

Time and Date of Analysis

Date: January 04, 2017 Time: 12:21:43

Anacapa Island, CA Single Anchor Design

PROPOSED DEPTH = 10.0 FT

REDUCTION FACTOR APPLIED FOR UPLIFT FRICTION = 1.000

NUMBER OF LAYERS = 1

WATER TABLE DEPTH = 82.0 FT.

FACTOR OF SAFETY APPLIED TO THE ULTIMATE SIDE FRICTION CAPACITY = 3.00

FACTOR OF SAFETY APPLIED TO THE ULTIMATE BASE CAPACITY = 3.00

SOIL INFORMATION

LAYER NO 1----WEAK ROCK

AT THE TOP

DIAMETER OF SOCKET, FT = 0.166E+01

SLUMP OF CONCRETE, IN = 0.500E+01

ANGLE OF INTERFACE FRICTION, DEG. = 0.360E+02

UNIAXIAL COMPRESSION STRENGTH OF ROCK,LB/SQ FT = 0.500E+05

ELASTIC MODULUS FOR THE INTACT ROCK, LB/SQ IN. = 0.500E+07

ROCK QUALITY DESIGNATION (RQD) % = 0.200E+02

DEPTH, FT = 0.000E+00

AT THE BOTTOM

DIAMETER OF SOCKET, FT = 0.166E+01

SLUMP OF CONCRETE, IN = 0.500E+01

ANGLE OF INTERFACE FRICTION, DEG. = 0.360E+02

UNIAXIAL COMPRESSION STRENGTH OF ROCK,LB/SQ FT = 0.500E+05

ELASTIC MODULUS FOR THE INTACT ROCK, LB/SQ IN. = 0.800E+07

ROCK QUALITY DESIGNATION (RQD) % = 0.300E+02

DEPTH, FT = 0.100E+03

DRILLED SHAFT INFORMATION

DIAMETER OF STEM = 0.660 FT.

DIAMETER OF BASE = 0.660 FT.

END OF STEM TO BASE = 0.000 FT.

ANGLE OF BELL = 0.000 DEG.

IGNORED TOP PORTION = 0.000 FT.

IGNORED BOTTOM PORTION = 0.000 FT.

AREA OF ONE PERCENT STEEL = 0.493 SQ.IN.

ELASTIC MODULUS, Ec = 0.360E+07 LB/SQ IN

VOLUME OF UNDERREAM = 0.000 CU.YDS.

PREDICTED RESULTS

QS = ULTIMATE SIDE RESISTANCE;

QB = ULTIMATE BASE RESISTANCE;

WT = WEIGHT OF DRILLED SHAFT (FOR UPLIFT CAPACITY ONLY);

QU = TOTAL ULTIMATE RESISTANCE;

QBD = TOTAL ALLOWABLE LOAD USING A FACTOR OF SAFETY

APPLIED TO THE ULTIMATE BASE RESISTANCE;

QDN = TOTAL ALLOWABLE LOAD USING FACTORS OF SAFETY

APPLIED TO THE ULTIMATE SIDE RESISTANCE AND

THE ULTIMATE BASE RESISTANCE.

LENGTH VOLUME QS WT QU QBD QDN QU/VOLUME

(FEET) (CU.YDS) (TONS) (TONS) (TONS) (TONS) (TONS) (TONS/CU.YDS)

5.0 0.06 37.55 0.13 37.68 37.68 12.65 594.69

10.0 0.13 75.11 0.26 75.36 75.36 25.29 594.69

LOAD SETTLEMENT RELATIONSHIP

TOP LOAD TOP MOVEMENT

TONS IN.

0.2745E+02 0.1793E-02 0.3579E+02 0.2689E-02 0.4742E+02 0.4034E-02 0.6331E+02 0.6051E-02 0.8445E+02 0.9076E-02 0.9951E+02 0.1361E-01 0.1071E+03 0.2042E-01 0.1171E+03 0.3063E-01 0.1302E+03 0.4595E-01 0.1474E+03 0.6892E-01 0.1700E+03 0.1034E+00 0.1996E+03 0.1551E+00 0.2104E+03 0.2490E+00 0.2104E+03 0.4980E+00 0.2104E+03 0.9960E+00