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247, Construct tennis court, Studies & Reports• • Gregory W. Axten GEOTECHNICAL CONSULTANT SOIL, FOUNDATION AND GEOLOGIC STUDIES File No. 1127.01 February 15, 1984 Mr. and Mrs. Ben K. Kazarian #14 Upper Blackwater Canyon Road Rolling Hills Estates, California 90174 SUBJECT: Limited Geotechnical Review #14 Upper Blackwater Canyon Road Rolling Hills Estates, CA 90274 Dear Mr. and Mrs. Kazarian: The purpose of this report is to present our opinions pertaining to the pos- sibility of constructing the proposed tennis court, hobby shop, and putting green with regard to on -site geotechnical conditions. The report is limited in scope. No subsurface work was performed. The scope of work consisted of checking with governmental agencies for any reports pertaining to previous geotechnical work performed on the property, a review of published geotechnical reports and maps pertaining to the site area, a visual examination of the site and surrounding area, and preparation of this report. Prior to completing construction plans and specifications, additional geotechnical consulting, including subsurface exploration, is recommended to confirm the findings herein and provide guidelines for grading and foundation design. GEOTECHNICAL DESCRIPTION According to the grading plan provided by South Bay Engineering, the proposed tennis court, hobby shop, and putting green will be located on the descending slope below the existing residence. Cut -fill grading techniques will be required to provide sites for these structures. The slope created will have a slope ratio of 2:1 (horizontal to vertical). The site area appears to be underlain by bedrock consisting of the Altamira Shale member of the Monterey Formation. These rocks typically consist of well -bedded siltstones, sandstones, and minor mudstone. Dark brown and brown clayey natural topsoils overlie the bedrock in the site area. These soils are typically 2 to 5-feet thick in this area.- Descication cracks were observed in these topsoils. These cracks indicate the soil is expansive, typical of most topsoils in the Palos Verdes Hills area. 316 Tejon Place - Palos Verdes Estates, CA 90274 - (213) 375-0010 P.O. Box 17207 - San Diego, CA 92117 - (619) 434-1477 File No. 1127.01 February 15, 1984 Page 2 !regQry W. Axten GEOTECHNICAL CONSULTANT Regional maps and our knowledge of the local area strongly indicate that bedding within the underlying bedrock generally dips northerly at angles that may range between 9 and 22 degrees. CONCLUSIONS AND RECOMMENDATIONS It is our opinion that the proposed tennis court, hobby shop, and putting green are feasible with regard to existing on -site geotechnical conditions. If the underlying bedrock is northerly dipping as regional data indicates, portions of the proposed cuts may undercut the existing bedding, leaving unsupported beds below the existing residence area. If such conditions are encountered, buttress -style stabilization fills and/or retaining walls may have to be used to provide additional support. The expansive nature of the on -site soils will require that slabs and founda- tions be reinforced to increase their resistance to movement. Foundations will also require deepening in order to penetrate the most active portion of the zone of soil subject to seasonal moisture variations and corresponding swell and shrink CLOSURE The consulting which is the subject of this report has been conducted to evaluate the feasibility of the proposed improvements from a geotechnical standpoint. The proposal does appear feasible. To gather more detailed information about site conditions, subsurface exploration and laboratory testing is recommended at a later date in the project, at such time as prelim- inary plans are approved by the controlling agencies. Subsurface exploration is outside the scope of the current consulting agreement. The conclusions herein are based upon limited review. No warranty of future site performance is expressed or implied. The opportunity to submit this review is appreciated. Should you have any questions, please call. Respectfully submitted, GREGORY W. AXTEN GEOTECHNICAL CONSULTANT Keith Ehlert ,Grego W. Project Geologist Principal Engineer • Gregory W. Axten GEOTECHNICAL CONSULTANT SOIL, FOUNDATION AND GEOLOGIC STUDIES File No. 1127.01 February 15, 1984 Mr. and Mrs. Ben K. Kazarian #14 Upper Blackwater Canyon Road Rolling Hills Estates, California 90174 SUBJECT: Limited Geotechnical Review #14 Upper Blackwater Canyon Road Rolling Hills Estates, CA 90274 Dear Mr. and Mrs. Kazarian: The purpose of this report is to present our opinions pertaining to the pos- sibility of constructing the proposed tennis court, hobby shop, and putting green with regard to on -site geotechnical conditions. The report is limited in scope. No subsurface work was performed. The scope of work consisted of checking with governmental agencies for any reports pertaining to previous geotechnical work performed on the property, a review of published geotechnical reports and maps pertaining to the site area, a visual examination of the site and surrounding area, and preparation of this report. Prior to completing construction plans and specifications, additional geotechnical consulting, including subsurface exploration, is recommended to confirm the findings herein and provide guidelines for grading and foundation design. GEOTECHNICAL DESCRIPTION According to the grading plan provided by South Bay Engineering, the proposed tennis court, hobby shop, and putting green will be located on the descending slope below the existing residence. Cut -fill grading techniques will be required to provide sites for these structures. The slope created will have a slope ratio of 2:1 (horizontal to vertical). The site area appears to be underlain by bedrock consisting of the Altamira Shale member of the Monterey Formation. These rocks typically consist of well -bedded siltstones, sandstones, and minor mudstone. Dark brown and brown clayey natural topsoils overlie the bedrock in the site area. These soils are typically 2 to 5-feet thick in this area.- Descication cracks were observed in these topsoils. These cracks indicate the soil is expansive, typical of most topsoils in the Palos Verdes Hills area. 316 Tejon Place - Palos Verdes Estates, CA 90274 - (213) 375-0010 P.O. Box 17207 - San Diego, CA 92117 - (619) 434-1477 File No. 1127.01 February 15, 1984 Page 2 !regQry en W. Ax t GEOTECHNICAL CONSULTANT Regional maps and our knowledge of the local area strongly indicate that bedding within the underlying bedrock generally dips northerly at angles that may range between 9 and 22 degrees. CONCLUSIONS AND RECOMMENDATIONS It is our opinion that the proposed tennis court, hobby shop, and putting green are feasible with regard to existing on -site geotechnical conditions. If the underlying bedrock is northerly dipping as regional data indicates, portions of the proposed cuts may undercut the existing bedding, leaving unsupported beds below the existing residence area. If such conditions are encountered, buttress -style stabilization fills and/or retaining walls may have to be used to provide additional support. The expansive nature of the on -site soils will require that slabs and founda- tions be reinforced to increase their resistance to movement. Foundations will also require deepening in order to penetrate the most active portion of the zone of soil subject to seasonal moisture variations and corresponding swell and shrink CLOSURE The consulting which is the subject of this report has been conducted to evaluate the feasibility of the proposed improvements from a geotechnical standpoint. The proposal does appear feasible: To gather more detailed information about site conditions, subsurface exploration and laboratory testing is recommended at a later date in the project, at such time as prelim- inary plans are approved by the controlling agencies. Subsurface exploration is outside the scope of the current consulting agreement. The conclusions herein are based upon limited review. No warranty of future site performance is expressed or implied. The opportunity to submit this review is appreciated. Should you have any questions, please call. Respectfully submitted, GREGORY W. AXTEN GEOTECHNICAL CONSULTANT L `-z_2i l Keith Ehlert Project Geologist Greg Prin ' pal neer