PROJECT INFORMATION EVALUATION PROCEDURES

Transcription

1 April 10, 2012 Board of Directors Hunters Ridge Amenities Association, Inc. 422 Hunters Circle Greenville, SC Attention: Mr. Jerry Miller Mr. Bruce Williams Re: Engineering Evaluation of Existing Pavement Hunters Ridge Subdivision Hunters Circle, Hunters Way, Hunters Court, and Calmar Court Greenville, South Carolina PARAGON Project No.1066 Gentlemen: Paragon Engineering & Geosciences, LLC (PARAGON) has completed our evaluation of the existing pavements within Hunters Circle, Hunters Way, Hunters Court, and Calmar Court in the Hunters Ridge Subdivision. The enclosed report describes our observations, the exploration and testing procedures, as well as our conclusions and recommendations. A Location Diagram and Hand Auger Boring Summary are attached to this report. PROJECT INFORMATION We understand that consideration is being given to replacing the existing pavements within Hunters Circle, Hunters Way, Hunters Court, and Calmar Court in the Hunters Ridge Subdivision. The existing pavements with the approximate 2,900 linear feet of roadways was originally constructed approximately 0 years ago and currently has varying degrees of wearing and distress. Once replaced, the roadways will primarily be utilized by automobile traffic with periodic garbage truck and small truck traffic. EVALUATION PROCEDURES On April 5, 2012, a visual walking reconnaissance of the existing pavements was performed. The general condition of the asphalt surfaces was noted and areas of visible pavement distress were identified. Where pavement distress was evident, the likely cause of the distress was assessed, if possible, by visual observation. In addition to the visual inspection of the pavements, the existing pavement sections and underlying subgrade conditions were evaluated at eighteen (18) locations. These locations were spaced at intervals not exceeding 200 feet between test locations at the approximate locations identified on the attached Location Diagram. At these locations, the asphalt was cored utilizing a 4-inch diameter core bit. A hand auger boring was then manually advanced through the cored hole to depths of 1 ½ to 6 feet below the ground surface. Dynamic Cone Penetrometer (DCP) tests were performed at selected vertical increments as the borings were advanced Woodruff Road, Suite G-18 Greenville, SC (864) Main (864) Fax

2 Hunters Ridge Subdivision Pavement Evaluation PARAGON Project No Greenville, South Carolina Page 2 The DCP test procedure involves first seating the conical point of the penetrometer 1 ¾ inches into the bearing materials. The conical point is then driven in 1 ¾-inch intervals using a 15- pound weight falling from a height of 20 inches. The penetrometer reading is the number of blows required to drive the conical point 1 ¾ inches following the initial seating and the penetrometer reading is recorded as number of blows per 1 ¾ inch increment (bpi). When properly evaluated, the penetrometer test results can provide an index for estimating soil strength and relative density. The test locations were field located by our engineering personnel by measuring distances from the existing site features and should be considered approximate. After completion of the drilling operations, the boreholes were backfilled with auger cuttings to the prevailing ground surface and the core holes were filled with asphalt patch. A field log of the soil encountered in the boring was maintained by a geotechnical engineer. The geotechnical engineer classified the retrieved soil cuttings on the basis of texture and plasticity in accordance with the Unified Soil Classification System (USCS). The group symbols for each soil type are indicated in parentheses following the soil descriptions on the Hand Auger Boring Summary. A brief explanation of the USCS is included with this report. The geotechnical engineer grouped the various soil types into the major zones noted on the Hand Auger Boring Summary. The stratification lines designating the interfaces between earth materials on the Hand Auger Boring Summary are approximate; in situ, the transitions may be gradual. OBERVATIONS & FINDINGS Observed Categories of Distress The observed pavement distress can generally be categorized as the following: Vertical Displacement: This condition is typically the result of settlement of the pavements due to consolidation of the subgrade soils under imposed traffic loads. While this condition is often the result of poorly compacted underground utility backfills, the lack of compaction of both the pavement base course and/or subgrade fill soils can result in vertical displacement. Alligator Cracking: Alligator cracking is caused by the overloading of the pavement support capabilities. This condition can be the result of very heavy traffic loads for which the pavement section was not designed to support, a pavement section that is too thin to support the vehicle traffic, weak subgrade soil support, or poor stormwater runoff or subsurface water drainage. Block Cracking: Block cracking is often the result of shrinkage of the asphalt pavements (asphalt and/or base course) over time. This shrinkage cracking typically occurs in a block type pattern. As asphalt ages it becomes more brittle and more susceptible to shrinkage. Block cracking can occur sooner than expected if the asphalt pavements remain unused or underutilized for extended periods of time. Potholes: Potholes are the result of sections of the asphalt pavement becoming dislodged or removed from the surrounding pavements resulting in a hole. This condition can sometimes occur due to gouging of the surface of the asphalt by equipment but often is the result of severe alligator cracking.

3 Hunters Ridge Subdivision Pavement Evaluation PARAGON Project No Greenville, South Carolina Page Observations & Test Results The following is a description of the observed pavement conditions and test results: Main Entrance Drive (Hunters Court) General This section of roadway has been previously removed and replaced. Since the placement of the new asphalt, evidence of distress has developed primarily within the inbound lane between Foothills Road and the gate along with isolated areas intermediate of the gates and the intersection with Calmar Court. The remainder of the asphalt appears to be in moderate to good condition. The pavement distress includes severe alligator cracking and moderate to severe vertical displacement of the asphalt pavement within the inbound lane both north and south of the gate. Isolated areas primarily in the outbound lane adjacent to the concrete curb, in the center of the drive, and over marked underground utility crossings. The photographs below depict the observed pavement distress: View of vertical displacement (rutting) and alligator cracking at inbound lane View of vertical displacement (rutting) and alligator cracking at inbound lane at gate View of alligator cracking extending through gate in inbound lane View of isolated areas in outbound lane with evidence of vertical displacement and alligator cracking

4 Hunters Ridge Subdivision Pavement Evaluation PARAGON Project No Greenville, South Carolina Page 4 Subsurface Conditions Borings HAB-1 and HAB-2 were performed within this section of roadway. The asphalt was measured to range from 1 ½ to 1 ¾ inches in thickness and was underlain by ½ to 4 inches of base course crushed stone that was observed to be contaminated with soil. Underlying the pavement at boring HAB-1 were moderately low to moderate consistency fill soils which consisted of silty sand (SM) and clayey sandy silt (ML) which exhibited DCP values ranging from 5 to 15 blows per increment (bpi). These DCP values would indicate the fill soils were poorly to moderately well compacted. Boring HAB-2 encountered previously cultivated soils to a depth of 1 ½ feet. These cultivated soils consisted of clayey sandy silt (ML) which exhibited a DCP results in excess of 20 bpi. These cultivated soils were underlain by residual soils consisting of clayey silt (ML) which exhibited a DCP value of 12 bpi. Hunters Court (from Calmar Court to cul-de-sac) General This section of roadway extends north from Calmar Court to a square cul-de-sac. There was evidence of patches within the cul-de-sac at two locations. These patches were in fair condition. Some grass was observed to be growing from some of the cracks within the asphalt. The cul-de-sac had evidence of minor alligator cracking primarily along the construction joints and block cracking. The section of roadway extending to the cul-de-sac had minor to moderate block cracking. No evidence of significant differences in elevation across the block cracks was observed. The photographs below depict the observed pavement distress: View of block cracking from shrinkage of the asphalt along roadway facing north View of block cracking from shrinkage of the asphalt in cul-de-sac

5 Hunters Ridge Subdivision Pavement Evaluation PARAGON Project No Greenville, South Carolina Page 5 View of block cracking and alligator cracking in cul-de-sac View of block cracking and alligator cracking in cul-de-sac Subsurface Conditions Boring HAB- was performed within the cul-de-sac section of this roadway. The asphalt was measured to be 2 ½ inches in thickness and was underlain by 4 ¼ inches of base course crushed stone. Underlying the pavement were moderate to low consistency fill soils which consisted of clayey sandy silt (ML) which exhibited DCP values ranging from to 12 blows per increment (bpi). These DCP values would indicate the fill soils were poorly to moderately well compacted. Calmar Court General There was evidence of patches within the sections of Calmar Court both east and west of its intersection with Hunters Court. These patches had evidence of distress which appeared to be the result of a lack of subgrade support. There was evidence of vertical displacement in front of the residences at 8 and 12 Calmar Court. This vertical displacement appeared to be the result of consolidation of the subgrade soils. Moderate to severe alligator cracking was observed from 6 Calmar Court to the 4-way intersection with Hunters Court along with from the 4-way intersection to the west end of Calmar Court. A pothole was observed near the west end of Calmar Court at its intersection with Hunters Circle. The photographs below depict the observed pavement distress: View of asphalt patch along curb View of severely cracked utility line patch

6 Hunters Ridge Subdivision Pavement Evaluation PARAGON Project No Greenville, South Carolina Page 6 View of cracked asphalt patch View of block cracking and previously patched area View of severe alligator cracking View of moderate to severe alligator cracking View of block cracking, open construction joint, and minor alligator cracking View of moderate to severe alligator cracking

7 Hunters Ridge Subdivision Pavement Evaluation PARAGON Project No Greenville, South Carolina Page 7 View of vertical displacement along utility line patch View of moderate to severe alligator cracking View of moderate to severe alligator cracking View of moderate to severe alligator cracking Subsurface Conditions Borings HAB-4 through HAB-10 were performed within this roadway. The asphalt was measured to range from 2 to ¾ inches in thickness and was underlain by 4 ⅛ to 5 ½ inches of base course crushed stone. Underlying the pavement were moderate to low consistency fill soils which consisted of clayey sandy silt (ML), clayey silt (ML), and sandy silt (ML) which exhibited DCP values ranging from 1 to in excess of 20 blows per increment (bpi). These DCP values would indicate the fill soils were poorly to moderately well compacted. Moderate consistency residual soils were encountered at borings HAB-4 and HAB-9 at depths of 2 feet and directly beneath the pavements, respectively. These residual soils consisted of clayey silt (ML) and sandy silt (ML) which exhibited DCP values ranging from 9 to 15 bpi. Hunters Circle General The asphalt pavements had evidence of severe alligator cracking from the south end of Hunters Circle at the gate to the residence at 404 Hunters Circle. Several asphalt patches are present within the cul-de-sac and appear to be in good condition. Block cracks are present over the remainder of the roadway and cul-de-sac areas.

8 Hunters Ridge Subdivision Pavement Evaluation Greenville, South Carolina PARAGON Project No Page 8 The photographs below depict the observed pavement distress: View of block cracking and severe alligator cracking within the southern end of roadway View of severe alligator cracking in roadway View of severe alligator cracking in roadway View of alligator cracking in roadway View of block cracking in roadway View of block cracking in cul-de-sac

9 Hunters Ridge Subdivision Pavement Evaluation Greenville, South Carolina View of block cracking in roadway PARAGON Project No Page 9 View of previous utility line asphalt patch in cul-de-sac Subsurface Conditions Borings HAB-11 through HAB-17 were performed within this roadway. The asphalt was measured to range from 1 ¼ to ¼ inches in thickness and was underlain by 4 to 6 ½ inches of base course crushed stone except at boring HAB-11. At HAB-11, the asphalt was underlain by 1 ½ inches of loose asphalt millings. Underlying the pavement were moderately low to moderate consistency fill soils which consisted of clayey sandy silt (ML), clayey silt (ML), and sandy silt (ML) which exhibited DCP values ranging from 5 to 22 blows per increment (bpi). These DCP values would indicate the fill soils were moderately to well compacted. Moderate consistency residual soils were encountered at borings HAB-10 to HAB-1 at depths ranging from directly beneath the pavements to 2 ½ feet. These residual soils consisted of clayey silt (ML), silty sand (SM), and sandy silt (ML) which exhibited DCP values ranging from 10 to 22 bpi. Amenities Parking Lot General Block cracks are present over the majority of the parking lot. No other evidence of pavement distress was observed. A photograph of the observed existing conditions is presented below: View of block cracking at amenities parking lot

10 Hunters Ridge Subdivision Pavement Evaluation Greenville, South Carolina PARAGON Project No Page 10 Subsurface Conditions Boring HAB-18 was performed within this parking lot. The asphalt was measured to be 1 ¼ inches in thickness and was underlain by 5 ½ inches of base course crushed stone. Underlying the pavement were moderately consistency fill soils which consisted of sandy silt (ML) which exhibited DCP values ranging from 14 to 18 blows per increment (bpi). These DCP values would indicate the fill soils were moderately to well compacted. CONCLUSIONS AND RECOMMENDATIONS Conclusions The existing pavements within the Hunters Ridge subdivision have evidence of distress that is more severe at many locations than would be expected for subdivision roadways of similar age. The observed distress within previously patched areas is more severe than is typically seen. Based upon our observations and the pavement and subgrade conditions encountered at the test location, it is our opinion that the extent and level of distress is the result of poor subgrade conditions due primarily to poorly compacted fill soils and utility trench backfills; a lack of adequate quality control during the original pavements; limited use of some of the roadways during periods of the development of the subdivision, and a constructed pavement section that was too thin to support the traffic loading for a residential subdivision. Recommendations The observed current pavement distress will likely worsen with repeated traffic loading and surface water infiltration through the existing cracks which will lead to softening of the base course and underlying subgrade soils. The current areas where cracking is present are expected to widen and the pavement integrity deteriorate as time passes. Due to the severity of the existing cracking as well as current curbing elevations, it will not be feasible to overlay the existing pavements with additional asphalt. The existing cracks would reflect through a surficial overlay section. Available repair options include the removal and replacement of the existing asphalt layer or the use of a full-depth reclamation process. Details for these options as well as potential limitations are presented below. We recommend the following two options be considered: Asphalt Removal and Replacement One option is the removal of the existing asphalt pavements, grading the base subgrade, and construction of a new pavement section. With this option, the existing asphalt could be milled and then hauled off site. After the asphalt is removed, the exposed base course layer would be graded to the required elevations to allow the construction of the new pavement section. Since the existing base course layer was relatively thin or non-existent (boring HAB-11) and was contaminated with soil at numerous test locations, the base course would need to be neglected in the analysis to determine the new pavement section. The near surface fill subgrade soils at numerous boring locations were assessed to be soft; therefore, some remediation of the subgrade conditions will likely be required and at some locations extensive to provide a stable subgrade to support the construction of the new asphalt section. For these reasons, it is important that the subgrades be evaluated just before pavement construction. At that time, as much of the subgrade as practical should be proofrolled with a loaded dump truck in the presence of a PARAGON engineer. Any areas that deflect significantly under the proofrolling load, or which are otherwise assessed to be soft or unstable, should be undercut to firm materials. The undercut areas

11 Hunters Ridge Subdivision Pavement Evaluation Greenville, South Carolina PARAGON Project No Page 11 should be backfilled with compacted soil or crushed stone. A PARAGON engineer can provide recommendations for repairing any unstable areas that are observed. Asphalt should be placed immediately following the completion of the indication of stable areas during the proofrolling to not allow the subgrade soil support conditions to deteriorate due to exposure to weather and construction traffic. Subgrade, base, and pavement construction operations and materials should meet the minimum requirements of South Carolina Department of Transportation s (SCDOT) Standard Specifications for Highway Construction, 2000 Edition. The existing graded aggregate base course (GABC) should be compacted to at least 100% of its modified Proctor maximum dry density as determined by ASTM D In-place density testing of the aggregate base course should be performed to verify that this compaction criterion is achieved. We recommend the following minimum new pavement thicknesses for the roadways: Pavement Type Standard Duty Asphalt Binder Course Asphalt Surface Course.0 inches 2.0 inches With this option, there is some potential for future pavement distress becoming evident due to long term consolidation induced settlement of the existing poorly compacted fill soils and utility trench backfills at some locations. Full Depth Reclamation - In lieu of removing and hauling away the existing asphalt pavements, another option for replacing the track is the use of a Full Depth Reclamation (FDR) process. FDR is a pavement rehabilitation technique in which the full flexible pavement section and a predetermined portion of the underlying materials are uniformly crushed, pulverized, or blended, resulting in a stabilized base course. While FDR can be utilized to depths exceeding 12 inches, depths of 6 to 9 inches is typical. Further stabilization should be obtained through the use of available additives such as asphalt emulsion or foamed asphalt. Additionally, Portland cement or fly ash can be blended with the new base for added compressive strength of the base course. After the existing asphalt is pulverized and the addition of chemical additives to stabilize the base material, the base material should be compacted to at least 98% of the material s standard Proctor maximum dry density. After this mixing process is completed and any required curing time has passed, as much of the subgrade as practical should be proofrolled with a loaded dump truck in the presence of a PARAGON engineer. Any areas that deflect significantly under the proofrolling load, or which are otherwise assessed to be soft or unstable, should be undercut to firm materials. The undercut areas should be backfilled with compacted crushed stone. A PARAGON engineer can provide recommendations for repairing any unstable areas that are observed.

12 Hunters Ridge Subdivision Pavement Evaluation Greenville, South Carolina PARAGON Project No Page 12 We recommend the following minimum pavement thicknesses for the roadway pavements if FDR is utilized: Pavement Type Standard Duty Cement Stabilized FDR Base Material 8 inches Asphalt Surface Course 2.0 inches With the FDR option, some excess material will be generated during the reclamation process and will require removal to achieve the desired elevation to allow the construction of the new asphalt section to match the current grades of the existing curbs. If the curbs are replaced, it is recommended raising the curbs the required height (approximately 2 inches) to greatly reduce the amount of material to be hauled off to establish the required elevations. Pavement Maintenance Routine maintenance should be performed as needed during the life of the asphalt pavements. Cracks that develop throughout the life of the asphalt should be thoroughly cleaned of debris (lanced) and then filled with a rubberized asphalt crack sealant. If the crack surfaces are not properly prepared, the sealant will not adhere. Crack filling should be accomplished every three to six years to prevent infiltration of water through the asphalt into the sub-grade, causing damage to the subbase. Generally, this type of repair should not be required for at least five years after asphalt placement. In addition to sealing any cracks which form in the asphalt, consideration should be given to the use of periodic seal coats on the asphalt surfaces. The purpose is to seal and add new life to a roadway surface. It protects the existing pavement but does not add significant structural strength. A surface treatment can range from a single, light application of emulsified asphalt as a fog seal, to a multiple-surface course made up of alternate applications of asphalt and fine aggregate. Seal coating of all asphalt pavements should be performed at approximately five- to eight- year intervals, or approximately twice during the service life of the asphalt pavement. Seal coating more often is generally not cost-effective. The material used should be impervious to petroleum products and should be applied after crack filling have been accomplished. Seal coating is a cost-effective way of extending the life of asphaltic concrete pavement. Seal coating is generally not scheduled for up to five years after an asphalt restoration project. We appreciate this opportunity to be of service to you. If you have any questions with regard to the information and recommendations presented in this report, or if we can be of further assistance to you in any way, please do not hesitate to contact us. Respectfully, Paragon Engineering & Geosciences, LLC Robin D. Bell, P.E. Principal Engineer Attachments: Location Diagram Unified Soil Classification System Hand Auger Boring Summary

13 HAB-15 HAB-16 HAB-14 HAB-1 HAB-4 HAB-10 HAB- HAB-5 HAB-12 HAB-9 HAB-18 HAB-7 HAB-6 HAB-11 HAB-8 HAB-2 HAB-17 HAB-1 LEGEND APPROXIMATE HAND AUGER BORING LOCATION LOCATION DIAGRAM HUNTERS RIDGE SUBDIVISION GREENVILLE, SOUTH CAROLINA PARAGON PROJECT NO. 1066

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15 HAND AUGER BORING SUMMARY HUNTERS RIDGE SUBDIVISION GREENVILLE, SOUTH CAROLINA PARAGON PROJECT NO HAB-1 ASPHALT (1 ¾ inches) GRADED AGGREGATE BASE ( ½ inches) mixed with soil 0 7 FILL: Tan orange silty fine to medium sand (SM) 7 4 FILL: Red clayey sandy silt (ML) 6 1 ½ HAB-2 HAB Terminated at 4 feet. DCP (bpi) DCP (bpi) ASPHALT (1 ½ inches) GRADED AGGREGATE BASE (4 inches) mixed with soil 0 1 ½ CULTIVATED SOILS: Brown clayey sandy silt (ML), organic stained ½ 4 RESIDUUM: Orange clayey silt (ML) 12 HAB Terminated at 4 feet. HAB- ASPHALT (2 ¼ inches) GRADED AGGREGATE BASE (4 ¼ inches) 0 6 FILL: Orange clayey sandy silt (ML), with some mica HAB Terminated at 4 feet. DCP (bpi)

16 HAB-4 HAND AUGER BORING SUMMARY HUNTERS RIDGE SUBDIVISION GREENVILLE, SOUTH CAROLINA PARAGON PROJECT NO DCP (bpi) ASPHALT ( ¾ inches) GRADED AGGREGATE BASE (5 ¼ inches) 0 FILL: Orange clayey sandy silt (ML) 2 FILL: Brown clayey silt (ML), with some roots, organic stained RESIDUUM: Red clayey silt (ML) 2 HAB Terminated at 4 feet. HAB-5 ASPHALT ( ½ inches) GRADED AGGREGATE BASE (5 inches) 0 4 FILL: Orange clayey sandy silt (ML), damp 1 2 ½ 4 HAB Terminated at 4 feet. HAB-6 ASPHALT ( inches) GRADED AGGREGATE BASE (5 inches) 0 FILL: Orange brown micaceous sandy silt (ML), with trace clay 1 2 Refusal met at feet DCP (bpi) DCP (bpi) 8 8

17 HAND AUGER BORING SUMMARY HUNTERS RIDGE SUBDIVISION GREENVILLE, SOUTH CAROLINA PARAGON PROJECT NO HAB-7 ASPHALT ( ½ inches) GRADED AGGREGATE BASE (5 ½ inches) 0 ½ FILL: Orange brown sandy silt (ML) ½ 4 FILL: Brown clayey silt (ML) 1 4 HAB-8 HAB Terminated at 4 feet. DCP (bpi) DCP (bpi) ASPHALT (2 ⅞ inches) GRADED AGGREGATE BASE (4 ⅛ inches) 0 2 ½ FILL: Orange brown sandy silt (ML) Refusal met at 2 ½ feet. HAB-9 ASPHALT (2 inches) GRADED AGGREGATE BASE (5 inches) 0 4 RESIDUUM: Orange & tan-brown micaceous sandy silt (ML) 1 4 HAB terminated at 4 feet. DCP (bpi)

18 HAND AUGER BORING SUMMARY HUNTERS RIDGE SUBDIVISION GREENVILLE, SOUTH CAROLINA PARAGON PROJECT NO HAB-10 ASPHALT (2 ¼ inches) GRADED AGGREGATE BASE (4 ¾ inches) 0 6 FILL: Tan brown micaceous sandy silt (ML), with some crushed stone 6 RESIDUUM: Tan-brown micaceous sandy silt (ML) 1 HAB-11 HAB terminated at feet. DCP (bpi) DCP (bpi) ASPHALT (1 ¼ inches) ASPHALT MILLINGS (1 ½ inches) 0 1 ½ FILL: Orange brown clayey sandy silt (ML) ½ 2 ½ FILL: Orange brown micaceous sandy silt (ML), damp ½ 4 RESIDUUM: Red orange clayey silt (ML), damp 4 HAB terminated at 4 feet. HAB DCP (bpi) ASPHALT (1 ¾ inches) GRADED AGGREGATE BASE (6 ¼ inches) 0 1 ½ FILL: Orange brown clayey sandy silt (ML) ½ RESIDUUM: Red orange clayey silt (ML), damp 14 HAB terminated at feet.

19 HAND AUGER BORING SUMMARY HUNTERS RIDGE SUBDIVISION GREENVILLE, SOUTH CAROLINA PARAGON PROJECT NO HAB-1 ASPHALT (1 ¼ inches) CRUSHED SNE/ SOIL MIXTURE (4 inches) GRADED AGGREGATE BASE ( inches) 0 4 RESIDUUM: Tan brown silty fine sand (SM) 1 2 HAB-14 HAB terminated at 4 feet. ASPHALT ( inches) GRADED AGGREGATE BASE (5 ½ inches) 0 FILL: Tan, orange, & brown micaceous sandy silt (ML) 1 2 HAB-15 Refusal met at feet. ASPHALT ( ¼ inches) GRADED AGGREGATE BASE (6 inches) 0 FILL: Orange brown sandy silt (ML) 1 2 Refusal met at feet. DCP (bpi) DCP (bpi) DCP (bpi) 15 1

20 HAND AUGER BORING SUMMARY HUNTERS RIDGE SUBDIVISION GREENVILLE, SOUTH CAROLINA PARAGON PROJECT NO HAB-16 DCP (bpi) ASPHALT (2 ¾ inches) GRADED AGGREGATE BASE (6 ½ inches) 0 2 FILL: Red orange clayey silt (ML) 1 19 Refusal met at 2 feet. HAB-17 DCP (bpi) ASPHALT (1 ¼ inches) GRADED AGGREGATE BASE (5 ½ inches) 0 1 ½ FILL: Red clayey silt (ML), damp 1 10 Refusal met at 1 ½ feet. HAB-18 ASPHALT (1 ¼ inches) GRADED AGGREGATE BASE (5 ½ inches) 0 4 FILL: Orange brown sandy silt (ML) HAB terminated at 4 feet. DCP (bpi)