Life Cycle Cost Analysis

Transcription

1 Life Cycle Cost Analysis Washington Street Widening 144 th Avenue to 148 th Avenue City of Thornton Deborah Turner, PE

2 Overview Project Location What is Life Cycle Cost Analysis? Project Background 7 Steps of Life Cycle Cost Analysis Project Schedule Construction Schedule 2

3 Project Location 3

4 Project Location Located in the North Washington Sub Area. Plan provides guidance for the type, intensity, and quality of future development. Region identified as next big area to development in Thornton with high visibility and access to Interstate 25 and E

5 What is LCCA Analytical tool using sound economic principles to evaluate the total cost of ownership between competing alternatives over the life of a project; Cradle to grave costs. Includes the following: Initial cost Cost of operation and maintenance Rehabilitation and resurfacing Cost to replace Considers differential costs among alternatives only since common costs cancel out. 5

6 LCCA 6

7 Objective of LCCA Used as one tool by our Senior Management team to choose the most cost effective material; in this case asphalt or concrete; in which to build Washington Street. The type of material chosen in this Phase will most likely be utilized for all phases of the project from 144 th Avenue to 160 th Avenue. 7

8 Challenges to overcome by LCCA Each Department has its own agenda of what is important. Project Manager- wants to minimize capital cost and stay within budget Streets Department- wants to minimize repair hours and avoid failures Traffic Engineering- wants to maximize traffic movement and minimize closures due to repairs Budget- wants to maximize value and minimize cost Stakeholders (Utilities, citizens, Bull Canal, landowners, oil/ gas companies, Parks Department, etc ) 8

9 Existing Conditions Existing 2-lane roadway from 144 th Avenue to 160 th Avenue 5-lane roadway south of 144 th Avenue, 6 lane roadway north of 160 th Avenue (Larkridge) Undeveloped farm land adjacent to roadway (high density, multifamily prairie dog development) Environmental Issues: Prairie Dogs, Raptor nests, Shay Ditch Drainage Channel (LOMR) Limited ROW Overhead Electric Transmission Lines Oil/Gas conflicts Utility relocations (water, electric, cable, phone) 9

10 Existing Conditions Existing 2-lane roadway from 144 th Avenue to 160 th Avenue 5-lane roadway south of 144 th Avenue, 6 lane roadway north of 160 th Avenue (Larkridge) Undeveloped farm land adjacent to roadway (high density, multifamily prairie dog development) Environmental Issues: Prairie Dogs, Raptor nests, Shay Ditch Drainage Channel (LOMR) Limited ROW Overhead Electric Transmission Lines Oil/Gas conflicts Utility relocations (water, electric, cable, phone) 9

11 Existing Conditions Existing 2-lane roadway from 144 th Avenue to 160 th Avenue 5-lane roadway south of 144 th Avenue, 6 lane roadway north of 160 th Avenue (Larkridge) Undeveloped farm land adjacent to roadway (high density, multifamily prairie dog development) Environmental Issues: Prairie Dogs, Raptor nests, Shay Ditch Drainage Channel (LOMR) Limited ROW Overhead Electric Transmission Lines Oil/Gas conflicts Utility relocations (water, electric, cable, phone) 9

12 Background Information 10

13 Background Information Located within the boundary of the North Washington Sub Area. 10

14 Background Information Located within the boundary of the North Washington Sub Area. Was completed in

15 Background Information Located within the boundary of the North Washington Sub Area. Was completed in 2005 Plan provides guidance for: land use (retail, corporate campus, and residential) density, and Created architectural standards to ensure a high quality. 10

16 Background Information Located within the boundary of the North Washington Sub Area. Was completed in 2005 Plan provides guidance for: land use (retail, corporate campus, and residential) density, and Created architectural standards to ensure a high quality. Area identified as next to develop in Thornton with high visibility and easy access to Interstate 25 and E

17 Background Information Completed by Matrix Design Group Analyzed the transportation options, pedestrian movement and drainage and Bull Canal relocation. 11

18 Background Information Stakeholders along with consultant recommended completing the full build out section (6 lanes). Construction costs only 15% more than a four lane section 12

19 Background Information Washington Street north of 160 th Avenue In Larkridge Development 13

20 Background Information Washington Street north of 160 th Avenue In Larkridge Development 13

21 Background Information Study recommended 5 separate and distinct project Phases to complete full project. 1 st segment was revised to include the Shay Ditch work and move the project boundary from 150 th Avenue to 147 th Avenue. Design of Phase 2 to be completed in

22 LCCA Process 1. Establish performance period to evaluate 2. Select typical sections and choose alternatives 3. Establish Agency Costs 4. Perform LCCA of typical sections. Is one clearly superior? 5. Select preliminary pavement type 6. Perform detailed pavement design 7. Select final pavement type and thickness. * Used DOT procedure 15

23 LCCA Process Step 1 Establish performance period to evaluate 16

24 Step 1-Evaluation Period Time period should be longer than the design period Long enough to incorporate the pavement type to be rehabilitated at least once Asphalt- 3 mill at year 10 and 4 mill at year 20 Concrete- grind at year year time period 17

25 LCCA Process Step 2 Select typical sections and choose alternatives 18

26 Step 2- Select Alternatives PSI complete Geotechnical Study in June 2010 and provided recommendations and design parameters Findings: Clayey sand, sandy clay, and silty sand Site soils have low to moderate swell potential >2% 19

27 Step 2-Design Information PSI Pavement Recommendations Subgrade 1. Asphalt Subgrade: 8 moisture conditioned and recompacted 2. Concrete Subgrade: 36 moisture conditioned and recompacted Pavement Sections investigated 1. Full Depth Asphalt Section: 11 inches HMA 2. Composite Asphalt Section: 7 inches HMA over 11.5 inches ABC 3. Geogrid Asphalt Section: 5 inches HMA over 15.5 inches ABC 4. Concrete Section: 9 inches 20

28 Design Information PSI Pavement Recommendations Final Pavement Recommendations with City requested Revisions 1. Full Depth Asphalt Section: 11 inches HMA with 8 moisture conditioned subgrade 2. Composite Asphalt Section: 7 inches HMA over 11.5 inches ABC w/ moisture cnd sg 3. Geogrid Asphalt Section: 6* inches HMA over 9 inches ABC w/ moisture cnd sg 4. Concrete Section: 9 inches with inches** moisture conditioned subgrade * City of Thornton standard practice for long term maintenance ** City of Thornton Standards do not allow concrete pavement without subgrade treatment for subgrade soils exhibiting swell potential greater than 2% when tested using a 200psf surcharge pressure. 21

29 LCCA Process Step 3 & Step 4 Establish Agency Costs/ Perform LCCA 22

30 LCCA Process- Agency Costs Initial Cost: Asphalt PG (4 ) PG 76-28(3 ) Concrete $45 per square yard $55 per ton $70 per ton Yields: Pavement Options Estimates* 1. Full Depth Asphalt Section: $8,323,000 Eliminated 2. Composite Asphalt Section: $8,115, Geogrid Asphalt Section: $7,922,000 Compare LCCA 4. Concrete Section: $8,885,000 Compare LCCA *$3.5 Million is associated with the Shay Ditch structure and channel improvements. 23

31 LCCA Process- Agency Costs Annual Maintenance: Asphalt $1,000 per lane mile per year Concrete $500 per lane mile per year *based on CDOT Yields (for 4.1 lane miles): Asphalt Concrete $4,102 per year $2,050 per year *based on CDOT 24

32 Rehabilitation: LCCA Process- Agency Costs Asphalt $70 per ton cost of asphalt $1.50 per SY for milling Concrete $3 per SY- diamond grinding at year 22 $150 per SY for slab replacement at year 22 *based on CDOT Yields (for 4.1 lane miles): Asphalt $337,500 for 3 mill at year 10 $425,000 for 4 mill at year 20 Concrete $62,036 for diamond grinding $43,320 for slab replacement 25

33 LCCA Process Step 5 Select Pavement Type 26

34 LCCA Process-Pavement Selection Final Result: Asphalt: Initial Construction $6,340,000 Maintenance $ 98,102 Rehab (year 10) $ 337,500 Rehab (year 20) $ 425,000 Total Cost $7,200,602 Concrete Initial Construction $6,942,000 Maintenance $ 49,051 Rehab (year 22) $ 109,400 Total Cost $7,100,451 27

35 LCCA Process-Pavement Selection Result: Concrete was ~$100,000 cheaper then asphalt over the 30 year life projection Asphalt was ~$600,000 cheaper then concrete initially Selection: Use Asphalt The decision was made by senior management based upon the LCCA, current budget, past pavement decisions, flexibility of asphalt, and current maintenance practices/ costs 28

36 LCCA Process Step 6 Perform Detailed Pavement Design 29

37 LCCA Process Evaluated 2 different Asphalt sections one with geogrid and one without 30

38 LCCA Process Step 7 Select final pavement type and thickness 31

39 LCCA Process-Pavement Selection HMA PG Grade Sx (20% RAP) HMA PG Grade S (20% RAP) ABC Class 6 Tensar TX5 Geogrid 8 excavated, moisture treated, and compacted subgrade 136 th Avenue: Cherry St to Holly St 32

40 Project Schedule Design Schedule 99% drawings are complete. Final drawings and specs due for City Review in March ROW is acquisition is almost complete. Project was delayed due to recently discovered oil/gas lines. 33

41 Project Schedule Construction schedule Anticipated construction advertisement in April 2012 with construction commencing in May Estimated 10-month construction. 34

42 Construction Phasing 35

43 Questions? City of Thornton Contact Information Deb Turner, Project Manager: Brett Henry, Senior Civil Engineer: