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HomeMy WebLinkAbout05-16-2017 Item 04 Railroad district sidewalk engineering standard modification Meeting Date: 5/16/2017 FROM: Daryl Grigsby, Public Works Director Prepared By: David Athey, Supervising Civil Engineer SUBJECT: RAILROAD DISTRICT SIDEWALK ENGINEERING STANDARD MODIFICATION RECOMMENDATION 1. Approve modifications to the Railroad District Sidewalk Engineering Standard 4150; and 2. Approve a new Railroad District Tree Well Engineering Standard 8135. DISCUSSION This staff report requests the approval of modifications to Engineering Standard 4150 and approval of new Engineering Standard 8135. Engineering Standard 4150 provides construction details for Railroad District boardwalk sidewalk. The proposed Engineering Standard 4150 modifications substitute colored concrete pavers for the current wood boardwalk sidewalk. This change was initiated to reduce ongoing maintenance requirements and risk of people tripping and falling. The establishment of Engineering Standard 8135 is being proposed to establish a new tree well standard for the board walk sidewalk. The new standard will bring railroad tree well construction in line with the rest of the City. The proposed Engineering Standards are a result of a year-long public review input process. Background The Railroad District sidewalk is one of three standard sidewalk designs within the City of San Luis Obispo. The other two standard designs include the downtown mission style sidewalk and regular sidewalk used throughout the City. The Railroad District Sidewalk Standard was established in 1998 along with the Railroad District Design Plan. The boardwalk sidewalk design is used to honor the historic and cultural roots that San Luis Obispo has with the railroad. Once installed, the boardwalk sidewalk works well for a couple of years but then starts to require excessive maintenance. Examples of required maintenance include protruding screws and warped, rotted, and splintered boards. A picture showing typical boardwalk sidewalk maintenance needs is shown to the right. Therefore, staff initiated a public process to change the sidewalk standard to eliminate the trip and fall hazards, provide a context appropriate sidewalk, and reduce long-term maintenance costs. City staff started the public input process by soliciting boardwalk sidewalk replacement ideas Picture 1 – Existing Boardwalk Sidewalk Packet Pg 25 4 from local design firms. A total of five different designs were submitted by local firms. The ideas ranged from stamped concrete to concrete pavers. Each of the designs included elements that would mimic boards or railroad track type elements. In addition, staff researched boardwalk replacement ideas including using recycled plastic decking, stamped concrete that mimics the look of wood, and hard woods such as Ipe as replacements. Staff visited Morro Bay to view both recycled plastic boardwalk and stamped concrete sidewalk. With this information, staff submitted a planning application to start the Boardwalk Standard Modification process. Public Works and Community Development staff worked together to present several design options to the Cultural Heritage Commission. Staff met with the Cultural Heritage Commission on August 24, 2015, to present options for boardwalk replacement. The replacement options included ideas ranging from brick and concrete pavers, stamped concrete, and wood replacements. A matrix comparing the benefits and disadvantages of each was presented to the Cultural Heritage Commission. Staff recommended the use of stamped concrete to maintain the appearance of wood planking. Other interested parties including Railroad Museum representatives spoke on the subject and supported the use of an alternative material. The Cultural Heritage Commission ultimately recommended that staff investigate the use of pavers rather than stamped concrete. In addition, the Cultural Heritage Commission requested that staff meet with the San Luis Obispo Railroad Museum group to gather input on the proposed substitute design. Public Works staff met with the San Luis Obispo Railroad Museum Board on December 8, 2015, to discuss the various options previously outlined at the Cultural Heritage Commission meeting. The Museum Board was not in favor of stamped concrete solution as it was perceived as too artificial for the historic district. The Railroad Museum Board also let staff know that while the boardwalk was meant to mimic the historic sidewalk in the area, no record of a wood boardwalk exists. After the Railroad Museum Board discussed the options, unanimous feedback was given for providing an option that included using pavers rather than stamped concrete or a wood substitute. In addition, the Railroad Museum Board also requested that the final paver design not include elements that mimic train tracks (rails and ties) since they have plans to include those elements in a sidewalk near the museum. Staff subsequently prepared a supplement to the planning application that outlined Public Works recommendation to substitute and investigate the use of pavers in lieu of the wood boardwalk. Since pavers were being recommended to be the substitute material, staff explored paver options that could be locally sourced, aesthetically pleasing, easily installed, and available in the long- term. Staff contacted local vendors to explore options for paver materials. Three pavers were ultimately chosen based on the four criteria. The selected material included one brick paver, and two concrete pavers with different colors. Three colors were chosen and a test installation of the three paver types was installed fronting 2098 Santa Barbara Avenue (Miner’s Hardware). A sign was erected explaining the test and asked the public for input. In addition, pictures of the three options were posted on Open City Government to solicit feedback from the public. The test and request for input was also announced on Public Works’ Facebook, Twitter, and Nextdoor websites. Pictures of the three options are shown below. Packet Pg 26 4 Staff received approximately 45 direct email responses related to the test installation. Staff also received nine statements from Open City Hall and had 45 separate visitors. The input from open City Hall is equivalent to 27 minutes of public comment. The comments from both the test installation and open City hall were just about evenly split between the wire cut red brick (Picture 3) and railroad blend concrete paver (Picture 4), with the Railroad blend paver getting more positive comments. Each of the surfaces have similar roughness when installed per the manufacturer’s recommendation and compliant with Americans with Disabilities Act (ADA) requirements. Based on Cultural Heritage Commission and public input the Boardwalk Engineering Standard 4150 (see Attachment A) was modified to include concrete pavers as in-lieu of a wood boardwalk. Concrete pavers provide easy installation, low long-term maintenance cost, and local availability. The concrete paver is proposed to be tumbled and installed flat side up in order to provide a smooth, flat surface. The tumbled paver gives an aged appearance. Based on public popularity the standard is proposed to use the “railroad blend” color (Picture 4, above). Included with the revised boardwalk standard, a new Tree Well Standard for the boardwalk area was developed. Currently, the City does not have an Engineering Standard for railroad district tree wells, as trees can grow through an opening in the boardwalk that is periodically cut wider to provide an area for the tree. The new standard includes the same tree grates that are currently installed around the city. Staff decided to develop a new standard to show how the frame and grate are integrated into the concrete pan under the pavers. The new Railroad District Tree Well Engineering Standard 8135 is included as Attachment B. CONCURRENCES Staff sent the final draft standards to all known Railroad District landowners as a final follow-up. Staff wanted to ensure that the landowners are aware of the proposed boardwalk change and new tree well standard. Staff notified the landowners that comments were being sought on the new standard and could be submitted by April 3rd. Staff has not received any comments as of April 10th. Community Development Department staff have reviewed and concur that the proposed Boardwalk Sidewalk standard changes are in conformance with the Cultural Heritage Packet Pg 27 4 Commission direction. ENVIRONMENTAL REVIEW This action is exempt from environmental review per CEQA Guidelines under the General Rule (Section 15061(b)(3)). It can be seen with certainty that adoption of Engineering Standards 4150 and 8135 could not have a significant effect on the environment. Specific projects that utilize Engineering Standards 4150 and 8135 will be subject to CEQA at the time the project is filed. FISCAL IMPACT There is no immediate public or private fiscal impact that will result from this change. This change does not require any landowner to install new or replace existing sidewalk. This change will guide future development and allow the replacement of the existing wood boardwalk with concrete pavers. The installation of this new sidewalk standard cost is roughly $125 per linear foot more than the wood boardwalk; however, the extra cost will pay for itself over time from reduced maintenance and public risk of tripping and falling. The current wood boardwalk lifespan is five to ten years. The new sidewalk lifespan is estimated to last more than 50-years. ALTERNATIVES 1. Choose a different paver material or color. Direct staff to investigate using a different paver material or color. While it is possible to find other colors and paver materials, the options provided are readily available from vendors within the City. 2. Reject staff’s proposed changes and keep the current wood boardwalk standard. Staff does not recommend this course of action based on the high maintenance costs and potential for trip and fall claims. Attachments: a - 4150 Rail Road Sidewalk Draft 04-13-2017 b - 8135 Rail Road Tree Well Draft 03-16-2017 Packet Pg 28 4 4"5' - 3 3 8" (VERIFY 16 PAVERS PER ROW PRIOR TO POURING FORMS) BRICK SIDEWALK RAILROAD DISTRICT 4150 New (Replaces former Boardwalk)JDL DA 3-17 January 2016 (addendum) REVISIONS BY APP DATE STANDARD CURRENT AS OF: SECTION A-A PLAN SECTION B-B A A 4" B 1 5 4" R = 14" SIDEWALK AND BASE PER ENG. STD. 4110 1 6 SEE ENG. STD. 4030 1 2 3 4 5 4 1 1"2 21 3 3 GENERAL NOTES: A. For use in Railroad District only. B. See Engineering Standard 8135 for Tree Well in Railroad District. INSTALLATION NOTES: DRAINAGE: Trowel a 3 4" wide x 1" deep weep slot at 10' O.C. sloping toward the drain outlet. Install a 3 4" diameter PVC drain pipe through curb face, aligned to bottom of troweled weep slots. Cover paver side of pipe with plastic window screen mesh and attach with zip tie. Cover mesh with tape during installation and remove tape after forms are removed. Pipe shall be cut flush with concrete. BEDDING SAND: 1" min. (2" at weep slots) concrete bedding sand in compliance with ASTM C33 specifications. PAVERS: Air Vol Block "Railroad Blend" tumbled concrete pavers or approved equal. Pavers shall be Type 1 and meet ASTM C902 specifications. Brick is not an approved equal. PATTERN: Pavers shall be installed in a standard "Running Bond" pattern. Cut pavers shall be no less than 2" long or wide. Surface of paver shall be set flush with curbs. COMPACTION: After pavers have been laid, sweep surface clean of any debris. ASTM C33 sand shall be swept into joints. Tamp the pavers into bedding sand with a plate compactor and vibrate sand up into joints. Adjust speed of compactor to run with high vibration, low amplitude, to avoid a jumping motion. Start at one edge of the sidewalk and compact the perimeter. Compact remaining area in 4" - 6" overlapping passes. Repeat process, compacting in opposite direction. Tamp pavers with at least two passes of the compactor at 90° angles to each other. Inspect and replace any broken pavers. PAVEMENT REMOVAL & REPAIR: See Engineering Standard 4110.6 1.5% SLOPE (1% MIN., 2% MAX.) 6" Packet Pg 29 4 Packet Pg 30 4