This master should be used by designers working on Port of Portland construction projects and by designers working for PDX tenants (“Tenants”). Usage notes highlight a few specific editing choices, however the entire section should be evaluated and edited to fit specific project needs.

SECTION 329119 –LANDSCAPE GRADING

PART 1 - GENERAL

1.1DESCRIPTION

  1. This section describes clearing, grading, placing fill material, and finish grading.

1.2REFERENCES

  1. AASHTO: American Association of State Highway Transportation Officials.
  2. AASHTO T180: Standard Method of Test for Moisture-Density Relations of Soils Using a 4.54-kg (10-lb) Rammer and a 457-mm (18-in.) Drop
  3. COP: City of Portland.

1.3RELATED WORK SPECIFIED ELSEWHERE

  1. Section 015713, Temporary Erosion, Sediment, and Pollution Control
  2. Section 329113, Soil Preparation

PART 2 - PRODUCTS

2.1DISPOSAL EXCAVATION

  1. Excess excavation and material not suitable for use as subgrade or embankment. This includes material excavated from grading areas and subgrade material that is unsuitable, as determined by the Port. Dispose of disposal excavation material where shown on the drawings.

2.2FILL MATERIAL

  1. Suitable onsite material approved for reuse as fill.

Choose one of the following two paragraphs.

  1. Clean sandy material obtained from a nearby Port source as shown on the drawings.
  2. Clean, friable, natural soil free of lumps, clay, debris, vegetation, and stones over oneinch maximum dimension, containing no decomposed stone, salts, or alkali.

PART 3 - EXECUTION

3.1EQUIPMENT

  1. Furnish and maintain earthmoving equipment in satisfactory condition and operate such equipment as necessary to control uniform density, section and smoothness of grade.

3.2REFERENCE POINTS

  1. Before starting work, locate all reference points. Take such steps as are necessary to prevent their dislocation or destruction. If destroyed or disturbed, replace as directed.

3.3CLEARING AND GRUBBING

  1. See Section 329113, Soil Preparation, for requirements of herbicide application prior to performing earthwork.
  2. Clear the site within the limits shown, removing brush and waste material that would interfere with the work. Dispose of waste material off site.
  3. Clear and remove existing vegetation prior to grading and working soil. Strip and stockpile existing top soil.

The following paragraph is a Port Environmental Affairs specification.

  1. Limit the total cleared and grubbed area excavations, and other disturbance, to only those areas necessary for the orderly flow of work.

3.4EXCAVATION AND GRADING

Modify A, B, and C if topsoil is added as a soil amendment in Section 329219.

  1. Excavate subgrade where necessary to allow for prepared soil mix, soil amendments, or fill material as required.

Fill in blank below with 3 inches for PDX or 6 inches for non-PDX.

  1. In lawn areas, grade material to _____ inches below top of curb if subsoil is sand or silt. Remove an additional 4 inches of material if subsoil is other than sand or silt and add 4 inches of sand material.

Fill in blank below with 5 inches for PDX or 8 inches for non-PDX.

  1. In planting areas, grade material to _____ inches below surrounding lawn finished grade or top of curb or sidewalk, if subsoil is sand or silt. Remove an additional 4 inches of material if subsoil is other than sand or silt and add 4 inches of sand material.
  2. In sidewalk areas, grade material as required for construction of sidewalk. Compact subgrade to 95percent of maximum density as measured by AASHTOT180.
  3. Subsoil material suitable for fill material may be stockpiled within the work area. Treat unsuitable material as disposal excavation.
  4. Do not place fill material until subgrade has been approved by the Port.
  5. Place and shape fill material to elevations and grades shown on the drawing, leaving room for any soil preparation amendments required. Use material within work area suitable for fill material, prior to hauling in additional fill material from the borrow site.
  6. Spread fill material in layers not to exceed 8 inches of uncompacted depth. Except as noted otherwise, compact fill material to 92 percent of maximum density as measured by AASHTOT180.
  7. Smoothly round abrupt change in slopes to avoid damming of surface drainage.
  8. Provide landscaped area with minimum 4inch crown where shown.
  9. Suspend earthwork when satisfactory results cannot be obtained on account of rain, freezing weather, or other unsatisfactory conditions of the field.
  10. Drag, blade, or slope the embankment to provide proper surface drainage to prevent ponding of water.
  11. Take care not to damage root zones of existing plant material to remain.

3.5WATERING

  1. There will be no payment made directly for watering. Watering will be considered an incidental part of the work.

3.6TOLERANCES

  1. The finished surface in landscape areas shall not deviate from the specified grade more than 0.10 foot asmeasured with a 10foot straightedge.
  2. Deviation in excess of these amounts shall be corrected by loosening, adding, or removing materials, reshaping and recompacting by sprinkling and rolling. A 10foot straightedge for testing shall be furnished by the Contractor.

3.7SIGN RELOCATION

  1. In turf areas to increase mowing efficiency, remove roadside signing and posts, i.e., “NoParking,” etc. Band signs to street light poles per City of Portland requirements. Mounting placement shall be consistent with previously mounted height and direction for visibility.

END OF SECTION329119

11/15/2018 / LANDSCAPE GRADING
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