Holdrege & Kull provides unique cost-effective rock bolting and ground anchor design services for towers and other structures with unusually high overturning or uplift forces. We have successfully used alternative anchoring methods to provide economical foundation design for telecommunications towers, roadway signs, ski lift towers, power transmission towers, crane foundations, and others. In addition, these methods are often appropriate value-engineering aspects for projects involving earth retaining systems, soil and rock stabilization, and temporary shoring. Based on our expertise, dramatic cost savings can be realized by designing the appropriate system based on a detailed understanding of soil and rock conditions.

ConstruCtion Quality assuranCeenvironmental

Ro c k Bo lt i n g, P i n n i n g, An c h o R i n g A n d Sh o R i n g

Professional Registrations

Geotechnical Engineer

Certified Engineering Geologist

Civil Engineer

Professional Geologist

Certified Hydrogeologist

Qualified SWPPP Developer/Practitioner

Certified Professional in Erosion and Sediment Control

H&K professional staff hold registrations in:

California, Nevada, Arizona, Utah, Oregon,

Washington, and Hawaii

Bloomer Hill Communications Tower - Butte County, California

Holdrege & Kull performed the geotechnical investigation for this new communication tower installation project. Based on the findings of our investigation, H&K developed an innovative design approach using high strength and small diameter micropiles as an alternative to conventional drilled shaft or mat foundations that require large volumes of concrete. The use of a micropile foundation reduced construction costs by an estimated $300,000 dollars, due to the expense associated with improving access roads to allow concrete delivery to this limited access site, and cut the projected 2-year construction schedule in half. Additionally, Butte County contracted H&K to provide the construction management services for this project.

BART Station - Pittsburg, California

West Bay Builders (WBB) was contracted to construct the new BART Station in Pittsburg, California, including the construction of an access tunnel for the station. The shoring contractor submitted a design for a 26-foot high temporary shotcrete soil nail wall to support Highway 4 during construction of the tunnel. Caltrans rejected the shoring plan stating that tie backs were not allowed under the highway right-of-way. WBB contacted Holdrege & Kull to provide an alternate plan. We determined that conventional soldier beam and wood lagging shoring would be too expensive, so we provided a plan to use removable Manta Ray mechanical anchors, which was acceptable to Caltrans. Boring logs for the project showed that the soil to be supported was dense clayey sand and silty sand. Based on the soil conditions, we eliminated the proposed shotcrete and instead used a more economical double twist hexagonal mesh facing between the tie backs, which was much faster to install.

Folsom Lake Emergency Spillway - Folsom California

Granite Construction was awarded the contract for Phase 3 of the Folsom Lake Emergency Spillway project. The contractor had to install rock bolts capable of supporting loads up to 745,000 pounds. Plans prepared by the Army Corps of Engineers (Corps) specified over 150 3-inch diameter bolts designed with a 25-foot bond length and an unbonded length of 30 feet. Due to limited site access and the difficulty in handling 55-foot long anchors, the contractor planned to connect a 25-foot rock bolt to a 30-foot rock bolt using a 5.5-inch diameter coupler, which in turn required a costly 7-inch diameter drilled hole in the resistant rock. H&K was asked to review the preliminary design and provide an alternate rock bolt design. Our analysis determined the most likely failure mode of the bolts would be between the grout and the bolt, rather than the rock itself. Our subsequent design using a single 25-foot long bolt with reduced 13-foot bond length not only reduced drilling depth by 12 feet, but also eliminated the need for couplings, thereby reducing the drilled hole diameter from 7 inches to 5.5 inches. H&K worked with the installation contractor to provide a bolt testing protocol and the design of load testing equipment for the project.

sWPPP GeoloGy & HydroGeoloGyGeotechnical

w w w . H o l d r e g e a n d K u l l . c o m

BR A n d X: co n v e n t i o n A l & co S t ly

h&k Alt e R n At i v e : vA l u e-en g i n e e R e d & co S t ef f e c t i v e

Fresno

559.389.5854

truCkee

530.587.5156

yuba City

530.671.0242

nevada City

530.478.1305

CHiCo

530.894.2487

Drill and blast high quality rock for

conventional deep foundation.

Remove rock fragments and

prepare excavation for rebar and

concrete.

Drill holes into high quality rock.

Place rebar in excavation.

Insert rock bolts and grout.

Fill excavation with low PSI concrete, cap with slab &

bolts.

Cap with slab.

“Based on the site location and the challenges we faced in transporting concrete, changing from the mat design to micropiles saved Butte County at least $300,000 and a costly delay in the project schedule. Holdrege and Kull’s staff, innovation and out-of-the-box thinking is what the tax payers of Butte County and California deserve”.

Ms. Weedy HannibalButte County - Manager Telecommunications

“Holdrege and Kull’s shoring plan for the New Bay Bridge W2 foundation excavations came through with flying colors despite two earthquakes and a dozen and a half explosive blasts.”

Mr. Leonard Fiji, PE, Caltrans