E-8 C15-2022-0017 ADV PACKET FEB 14 PART2 — original pdf

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E-8/17E-8/18E-8/19E-8/20BOARD OF ADJUSTMENT/SIGN REVIEW BOARD MEETING MINUTES (March 9, 2015) The Board of Adjustment/Sign Review Board convened in a meeting on March 9, 2015, City Council Chambers, 301 West 2nd Street, Austin, Texas. Chair Jeff Jack called the Board Meeting to order at 5:40 p.m. Board Members in Attendance: Jeff Jack (Chair), Melissa Hawthorne (Vice Chair), Sallie Burchett, Stuart Hampton (Alternate), Vincent Harding, Michael Von Ohlen, Will Schnier (Alternate) and Cathy French (SRB) Board Member Absent –Ricardo De Camps and Bryan King Staff in Attendance: Leane Heldenfels, Cindy Crosby (COA Attorney), Diana Ramirez EXECUTIVE SESSION (No public discussion) The Board of Adjustment/Sign Review Board will announce it will go into Executive Session, if necessary, pursuant to Chapter 551 of the Texas Government Code, to receive advice from Legal Counsel on matters specifically listed on this agenda. The Board of Adjustment/Sign Review Board may also announce it will go into Executive Session, if necessary, to receive advice from Legal Counsel regarding any other item on this agenda. Private Consultation with Attorney – Section 551.071 A APPROVAL OF MINUTES A-1 February 9, 2015 Board Member Vincent Harding motion to Approve the minutes for February 9, 2015; Board Member Melissa Hawthorne second on 6-0-2 vote (Board members Sallie Burchett and Will Schnier Abstained); APPROVED MINUTES FOR February 9, 2015. B. SIGN REVIEW BOARD RECONSIDERATIONS NONE E-8/21BOARD F. POSTPONEMENTS OF NONE ADJUSTMENT INTERPRETATION PREVIOUS G. BOARD OF ADJUSTMENT INTERPRETATION NEW PUBLIC HEARINGS G-1 C15-2015-0039 Betsy Greenberg for Heritage Neighborhood Association 2910 Rio Grande The appellant has requested the Board of Adjustment interpret whether staff erred in issuing a building permit at 2910 Rio Grande Street because: A. the garage that encroaches on 2910 Rio Grande does not qualify for an Exception from Compliance under Section 25-1-365, because a Certificate of Occupancy for the site has existed since 1983; and further that B. staff determined that Section 25-2-961 (Noncomplying Structures Defined) and 963 (Modification and Maintenance of Noncomplying Structures) applies to the existing garage since a structure which pre-dates applicable site development regulations may remain in its current configuration, however this determination does not address questions of additional development occurring on the site. The public hearing was closed on Board Member Will Schnier motion to Dismiss Item A as not applicable to the board’s authority and Deny Item B, Board Member Vincent Harding second on a 6-1 vote (Board member Stuart Hampton nay); DISMISSED ITEM A AS NOT APPLICABLE TO THE BOARD’S AUTHORITYAND DENIED ITEM B. H. BOARD POSTPONEMENTS OF ADJUSTMENT RECONSIDERATION PREVIOUS H-1 C15-2015-0005 William Hodge for Lark Miller 1210 Angelina Street The applicant has requested a variance(s) from Section 25-2-492 (D) (Site Development Regulations) to: (requested); and to A. decrease the minimum size lot from 5,750 square feet (required) to 1,129 square feet increase the impervious cover from 45% (required) to 56% (requested); and to B. C. decrease the front yard setback from 25 feet (required) to 10 feet (requested); in order to construct a single family home in a “SF-3-NP”, Family Residence – Neighborhood Plan zoning district. (Holly) The public hearing was closed on Board Member Sallie Burchett motion to Grant Item A with a condition that site be limited to .4 FAR and Withdraw Items B & C by Applicant, Board Member Michael Von Ohlen second on a 7-0 vote; GRANTED ITEM A WITH CONDITION OF SITE LIMITED TO .4 FAR AND WITHDRAW OF ITEMS B AND C BY APPLICANT. E-8/22E-8/23E-8/24E-8/25E-8/26Zoning Guide Residential Districts September 2016 SF-3 Family Residence Family Residence district is intended as an area for moderate density single-family residential use, with a minimum lot size of 5,750 square feet. Duplex use is permitted under development standards that maintain single-family neighborhood characteristics. This district is appropriate for existing single-family neighborhoods having typically moderate sized lot patterns, as well as for development of additional family housing areas with minimum land requirements. Site Development Standards Lot Minimum Lot Size Minimum Lot Width Maximum Units Per Lot Maximum Building Coverage Maximum Impervious Cover Massing 5,750 sq ft Maximum Height 50 ft 1 40% 45% Minimum Setbacks Front yard Street side yard Interior side yard Rear yard 35 ft 25 ft 15 ft 5 ft 10 ft Permitted and Conditional Uses † For detail on marked uses in the Family Residence district, see the Austin City Code 25-2-552. Residential Bed and Breakfast Residential (Group 1) * Duplex Residential * Retirement Housing (Small Site) † * Short-Term Rental Single-Family Attached Residential * Single-Family Residential * Two-Family Residential * Civic Club or Lodge (c) * College and University Facilities (c) * Communication Service Facilities * Community Events * Community Recreation—Public (c) * Community Recreation—Private (c) * Cultural Services (c) Day Care Services—Commercial (c) Day Care Services—General (c) Day Care Services—Limited Commercial Special Use—Historic (c) * 16 Family Home * Group Home Class I—General (c) * Group Home Class I—Limited * Local Utility Services (c) Private Primary Educational Services (c) * Private Secondary Educational Services (c) * Public Primary Educational Services * Public Secondary Educational Services * Religious Assembly Safety Services (c) Agricultural Community Garden Urban Farm * City of Austin E-8/27E-8/28E-8/29E-8/30E-8/31E-8/32E-8/33E-8/34E-8/35E-8/36E-8/37E-8/38 TABLE OF CONTENTS PAGE INTRODUCTION .......................................................................................................... 1 SCOPE ............................................................................................................................ 1 SITE DESCRIPTION ..................................................................................................... 2 FIELD TEST AND SAMPLING.................................................................................... 2 SUBSURFACE CONDITIONS ..................................................................................... 2 DISCUSSION AND RECOMMENDATIONS .............................................................. 3 FOUNDATION RECOMMENDATIONS ..................................................................... 4 QUALITY CONTROL PROGRAM .............................................................................. 6 LIMITATIONS ............................................................................................................... 7 APPENDIX SELECT FILL SPECIFICATIONS .........................................................................1 VICINITY MAP & GENERALIZED BORING LOCATION PLAN (2) ..............2 LOGS OF BORINGS (2) AND BORING LOGS TERMS & SYMBOLS .......................................................3 ENGINEERING, INC. 2220 Barton Skyway Austin, Texas 78704 Ph. (512) 447-8166 Fax (512) 447-0852 E-8/39SUBSURFACE INVESTIGATION FOUNDATION RECOMMENDATIONS AND FOR KUMAR RESIDENCE 1210 ANGELINA STREET AUSTIN, TEXAS INTRODUCTION An exploration of subsurface soil conditions for the proposed Kumar residence was authorized by Mr. Sanjiv Kumar on 2 September 2021 in accordance with our proposal dated 2 September 2021. The purpose of this investigation is to determine subsurface conditions and materials at the site in order to establish design and construction recommendations for the project's foundation system. SCOPE Our investigation consisted of the following: A. Laying out and drilling two borings to a depth of 20 feet below B. Logging the boring in the field and making a visual reconnaissance of existing grade. the area's terrain. Performing field tests. Taking samples of selected subsurface soils for laboratory tests. Making foundation recommendations based on engineering analysis of field notes and laboratory test results. C. D. E. 1 ENGINEERING, INC. 2220 Barton Skyway Austin, Texas 78704 Ph. (512) 447-8166 Fax (512) 447-0852 E-8/40SITE DESCRIPTION The proposed Kumar residence is located at 1210 Angelina Street in Austin, Texas. The site consists of a vacant lot. The lot is mostly flat and is covered with natural grasses. FIELD TEST AND SAMPLING The borings were made with a CME 55 truck mounted drilling rig. The holes were drilled using 4-inch diameter flight augers. The soil conditions were logged, and materials visually classified by the soil engineer in the field. Undisturbed samples were taken using a thin wall Shelby tube sampler. Disturbed samples were taken, and standard penetration tests were performed using a 2-inch O.D. split-barrel sampler driven by a 140-pound hammer dropping a distance of 30 inches. The number of blows to drive the sampler 12 inches is recorded and shown on the attached Log of Boring. SUBSURFACE CONDITIONS The soil conditions are described in more detail by the attached soil boring log. The property is located in what is geologically referred to as the Upper Colorado River Terrace Formation overlaying the Austin Chalk Formation. The Upper Colorado River Terrace formation consists of gravel, silt, sand, and clay and the Austin Chalk formation consists of chalk, marly limestone, and limestone. Fill is found on the surface to a depth of 18 inches. A tan clayey sand to sandy clay is then found to a depth of 12 to 12.5 feet. Then a layer of tan limestone rock is found and extends to termination of the borings at 20 feet. The clayey sand and sandy clay layer contain small to medium sized gravel becoming more clayey with depth and is medium dense to dense. The clayey sands are moderate to high in plasticity. The tan limestone rock is medium hard to hard and contains marl layers. Groundwater was not found in the boring and the hole was dry upon completion of the drilling operation; however, water migrates through the fractures, seams and joints in the rock and may be found near the surface after heavy rains. 2 ENGINEERING, INC. 2220 Barton Skyway Austin, Texas 78704 Ph. (512) 447-8166 Fax (512) 447-0852 E-8/41DISCUSSION AND RECOMMENDATIONS It is our understanding the residence will consist of a two-story house with a basement. We expect the foundation will be about 8 to 10 feet below grade and reinforced concrete basement walls will be used on the lower level and support the upper levels. After excavating to the basement subgrade, the soils are suitable for a shallow foundation consisting of continuous wall footings with a soil supported floor slab. Perimeter beams seated 12 inches into undisturbed tan clayey sand or tan limestone rock may be sized for an allowable bearing value of 3,500 PSF. Isolated column loads may be carried on spot footings established 24 inches into tan limestone rock and sized for an allowable bearing value of 4,000 PSF. The floor slab should be soil supported. Intermediate stiffening beams are optional. The soil conditions are also suitable for a reinforced concrete mat foundation. The mat foundation may be designed for a uniform allowable loading of 1,500 PSF when placed on the tan clayey sand approximately 8 to 10 feet below existing grade. The building pad should be prepared by excavating to the basement subgrade at approximately 8 to 10 feet below existing grade. The basement slab should be placed on a capillary barrier consisting of a minimum of 6 inches of washed pea gravel and covered with a high-quality vapor barrier. An underdrain should be constructed below the capillary barrier which consist of 4-inch diameter perforated PVC pipe placed a minimum of 12 inches below the finished slab level. The underdrain should be sloped to drain to a sump with an electric pump. We expect a basement type wall will be used at the lower level. Where below grade walls and slabs are constructed, it is essential to properly waterproof below the slab and behind concrete walls. The basement slab should be placed on a capillary barrier consisting of a minimum of 6 inches of 3/8 inch diameter washed pea gravel and covered with a high- quality vapor barrier. An underdrain should be constructed below the capillary barrier and consist of one or more trenches 12 inches deep and 12 inches wide with a 4-inch diameter perforated PVC pipe backfilled with one-inch gravel. The underdrain should be sloped to drain to a sump with an electric pump. Backfill against walls should be a minimum of 36 inches thick and consist of a one-inch diameter uniformly graded free draining crushed rock 3 ENGINEERING, INC. 2220 Barton Skyway Austin, Texas 78704 Ph. (512) 447-8166 Fax (512) 447-0852 E-8/42or washed gravel. To within 24-incjes of the surface. The final 24 inches should consist of clay backfill. The walls should be waterproofed with an asphaltic mastic or other approved product. Collector drains behind the walls will be necessary to remove groundwater seepage. Collection pipes should be placed a minimum of 12 inches below the finished slab level and sloped to drain to a sump with an electric pump. If these conditions are met, a coefficient of horizontal component of earth pressure of 45 PSF/LF of wall can be used for the active earth pressure condition and 55 PSF/LF of wall for the at-rest condition. Some variations may be encountered when the foundation is excavated. We recommend that inspections be made by the Geotechnincal engineer during excavation to verify proper bearing strata and footing seating depths have been achieved. It should be noted, no site plan with floor elevations or grading plan was available at the time our report was completed. We would like to review the drawings prior to final completion to determine if our recommendations have been properly interpreted and to make comments or suggestions for improvements. FOUNDATION RECOMMENDATIONS A. Shallow Foundation System: This foundation consists of continuous reinforced concrete spread footings with a soil supported floor slab. The slab is poured monolithically with grid system of intermediate stiffening beams. Heavy column loads are carried on spread footings. 1. Building Pad Excavate to the basement subgrade at approximately 8 to 10 feet below existing grade. The basement slab should be placed on a capillary barrier consisting of a minimum of 6 inches of washed pea gravel and covered with a high-quality vapor barrier. An underdrain should be constructed below the capillary barrier which consist of one or more trenches 12 inches wide and 12 inches deep with 4-inch diameter perforated PVC pipe and backfilled with one-inch gravel. The underdrain should be sloped to drain to a sump with an electric pump. 4 ENGINEERING, INC. 2220 Barton Skyway Austin, Texas 78704 Ph. (512) 447-8166 Fax (512) 447-0852 E-8/432. Beams and Floor Slab Trench for perimeter beams (wall footings) and stiffening beams. Place a vapor barrier between foundation soil. Immediately after placing reinforcing steel, pour beams and floor slab monolithically. 3. Soil Bearing Pressure and Seating Depths Perimeter beams should be seated 12 inches into undisturbed tan clayey sand or limestone rock and sized for an allowable bearing value of 3,500 PSF. Isolated column loads may be carried on widened grade beams or square spot footings established 24 inches into tan limestone rock and sized for an allowable bearing value of 4,000 PSF. 4. Basement Walls Basement walls should be properly waterproofed with an asphaltic mastic or other approved product. Backfill against walls should be a minimum of 36 inches thick and consist of a one-inch diameter uniformly graded free draining crushed rock or washed gravel. Collector drains behind the walls will be necessary to remove groundwater seepage. Collection pipes should be a minimum of 4-inch diameter perforated PVC pipe placed a minimum of 12 inches below the finished slab level and sloped to drain to a sump with an electric pump. Drainage Slope grounds away from foundation to provide rapid drainage. 5. B. Mat Foundation: 1. Reinforced Concrete Mat The mat foundation may be designed for a uniform allowable loading of 1,500 PSF when placed on the tan clayey sand approximately 8 to 10 feet below existing grade. 2. Building Pad Excavate to the basement subgrade at approximately 8 to 10 feet below existing grade. The basement slab should be placed on a capillary barrier consisting of a minimum of 6 inches of washed pea gravel and covered with a high-quality vapor barrier. An underdrain should be constructed below the capillary barrier and consist of one or more trenches 12 inches wide by 12 inches deep with a 4-inch diameter perforated PVC pipe 5 ENGINEERING, INC. 2220 Barton Skyway Austin, Texas 78704 Ph. (512) 447-8166 Fax (512) 447-0852 E-8/44backfilled with one-inch gravel. The underdrain should be sloped to drain to a sump with an electric pump. 3. Basement Walls Basement walls should be properly waterproofed with an asphaltic mastic or other approved product. Backfill against walls should be a minimum of 36 inches thick and consist of a one-inch diameter uniformly graded free draining crushed rock or washed gravel. Collector drains behind the walls will be necessary to remove groundwater seepage. Collection pipes should be a minimum of 4-inch diameter perforated PVC pipe placed a minimum of 12 inches below the finished slab level and sloped to drain to a sump with an electric pump. QUALITY CONTROL PROGRAM We recommend a Quality Control Program be implemented by the Owner or Architect to inspect the construction of the foundation and framing to verify all work is being performed in accordance with the approved engineered drawings and specifications. The inspections should include (but not be limited to) preparation of the building pad subgrade and placement and compaction of all fill material to verify proper density and moisture content. Inspections should be conducted on all foundation beams, piers and footings to verify proper bearing and seating depth. Where drilled piers are used or driven piles are installed, then full time inspection is recommended to verify proper bearing capacity is achieved. Pre-pour inspections should be made in order to verify proper placement of the reinforcement. All concrete should be inspected during placement for proper slump, air- content and temperature. Test cylinders should be made to verify compressive strength. French drains, under-drains, waterproofing and capillary barriers should be inspected prior to backfilling. All plumbing should be leak tested both before the slab is poured and after concrete is placed. Framing should be inspected to verify all floor trusses and roof members (trusses) are placed in accordance with the approved drawings. Anchor bolts and wind bracing should also be inspected. Welding and bolting on structural steel framing and connections should be inspected by a certified welding inspector. Reports of all inspections and tests should be forwarded to the Owner, Architect, Engineer, and Contractor. We can 6 ENGINEERING, INC. 2220 Barton Skyway Austin, Texas 78704 Ph. (512) 447-8166 Fax (512) 447-0852 E-8/45provide these services upon request. LIMITATIONS This report has been prepared in order to aid in the evaluation of this property and to assist the architect and engineer in the design of the project. It is intended for use with regard to specific projects discussed in general herein and any substantial changes in locations or grades should be brought to our attention so that we may determine how this may affect our conclusions. If during the proposed construction the soil strata are found to differ from that reported here, we should be notified immediately. This report contains a soil boring log that is for the purpose of arriving at foundation criteria and is not to be used by the excavation contractor in arriving at rock hardness or rock depth. The soil boring was drilled for the purpose of providing foundation design criteria such as bearing values and footing seating depths. This report is not intended to be a detailed study of groundwater conditions. The presence or absence of water in our boring may not represent the groundwater conditions under all seasonal conditions. No long-term groundwater monitoring was performed in the preparation of this report. The procedures, tests and recommendations of this investigation and report have been conducted and furnished in accordance with generally accepted professional engineering practices in the field of foundations, engineering soil mechanics and engineering geology. No other warranty is either expressed or implied. 7 ENGINEERING, INC. 2220 Barton Skyway Austin, Texas 78704 Ph. (512) 447-8166 Fax (512) 447-0852 E-8/46APPENDIX ITEM 1 ENGINEERING, INC. 2220 Barton Skyway Austin, Texas 78704 Ph. (512) 447-8166 Fax (512) 447-0852 E-8/47SELECT FILL SPECIFICATIONS SELECT FILL Select fill as called for on the plans shall meet one of the following requirements (% Passing or % Retained) as verified by the Engineer when properly slaked and tested by standard laboratory methods: % Retained Or 2 ½" Screen 1 ½" Screen 7/8" Screen No. 4 Sieve No. 40 Sieve 0% 0% - 25% 15% - 55% 45% - 75% 60% - 90% % Passing 100% 75% - 100% 45% - 85% 25% - 55% 10% - 40% Material passing the No. 40 sieve shall have a minimum plasticity index of 3 and shall not have a plasticity index of greater than 18. COMPACTION OF FILL Select fill shall be placed in lifts not to exceed 8 inches loose measure and compacted to 95% or greater of the maximum dry density as determined in accordance with TxDOT test method TEX 113E. Field densities shall be checked in accordance with ASTM D-6938 (Nuclear Gauge) to ensure compliance with project specifications. Select fill should be processed and moisture conditioned as needed to meet requirements of project moisture specifications. Samples of fill shall be furnished to the testing laboratory seven days prior to installation to permit time for specification compliance, inspection, and approval. ENGINEERING, INC. 2220 Barton Skyway – Austin, Texas – 78704 – Ph. (512) 447-8166 – Fax (512) 447-0852 E-8/48APPENDIX ITEM 2 ENGINEERING, INC. 2220 Barton Skyway – Austin, Texas – 78704 – Ph. (512) 447-8166 – Fax (512) 447-0852 E-8/49Not to Scale File No 09-30621 Holt Engineering, Inc. . TBPE Firm Registration No. F-430 - 2220 Barton Skyway . Austin, Texas 78704 VICINITY MAP KUMAR RESIDENCE 1210 ANGELINA STREET AUSTIN, TEXAS E-8/50B-02 B-01 N Not to Scale GENERALIZED BORING LOCATION PLAN KUMAR RESIDENCE 1210 ANGELINA STREET AUSTIN, TEXAS File No. 09-30621 Holt Engineering, Inc. . TBPE Firm Registration No. F-430 - 2220 Barton Skyway . Austin, Texas 78704 E-8/51APPENDIX ITEM 3 ENGINEERING, INC. 2220 Barton Skyway Austin, Texas 78704 Ph. (512) 447-8166 Fax (512) 447-0852 E-8/52E-8/53E-8/54BORING LOGS – TERMS & SYMBOLS SOIL TYPES Silt Clay Silty Sand Clayey Sand Sand Gravel Silty Clay or Clayey Silt Shale Limestone Silty clay w/Gravel Rock/Fragments Asphalt Crushed limestone base Sandstone Tan Limestone w/Interbedded Silt Layers Concrete SAMPLER TYPES Standard Penetration Test PARTICLE SIZE (ASTM D2487) Rock Core Seamless Push Shelby Tube Grab Sample Boulders >12 in. Coarse Sand 5 mm – 2 mm Silt 0.075 mm – 0.005 mm Cobbles 12 in. – 3 in. Medium Sand 2 mm – 0.4 mm Clay < 0.005 mm Gravel 3 in. – 5 mm Fine Sand 0.4 mm – 0.075 mm STRENGTH OF COHESIVE SOILS DENSITY OF GRANULAR SOILS CONSISTENCY COMPRESSIVE STRENGTH (TSF) NUMBER OF BLOWS PER FT., N < 0.25 0.25 to 0.50 0.50 to 1.0 1.0 to 2.0 2.0 to 4.0 > 4.0 0 – 4 4 – 10 10 – 30 30 – 50 Over 50 RELATIVE DENSITY Very Loose Loose Medium Dense Dense Very Dense Structure Description (ASTM D2488) Percentages of Sand & Gravel (ASTM D2488) Alternating layers of varying material or color with layers at least 6 mm thick Trace < 5% Alternating layers of varying material or color with the layers less than 6 mm thick Few 5% to 10% Breaks along definite planes of fracture with little resistance to fracturing Little 15% to 25% Slickensided Fracture planes appear polished or glossy, sometimes striated Some 30% to 45% Cohesive soil that can be broken down into small angular lumps which resist further breakdown Mostly 50% to 100% Inclusion of small pockets of different soils, such as small lenses of sand scattered through a mass of clay Criteria for Describing Moisture Conditions (ASTM D2488) Homogeneous Same color and appearance throughout Absence of moisture, dusty, dry to the touch Dry Moist Wet Damp but no visible water Visible free water, usually soil is below water table ENGINEERING, INC. 2220 Barton Skyway Austin, Texas 78704 Ph. (512) 447-8166 Fax (512) 447-0852 Very Soft Soft Firm Stiff Very Stiff Hard Stratified Laminated Fissured Blocky Lensed E-8/55