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HomeMy WebLinkAboutGeotechnical Eng Report-032321 Geotechnical Investigation Report D:\Jobs File\JBS 2019\019119CR\GI, Lot 4A, Gallatin Park Drive, BZ, MT.doc CLIENT: North Fork Builders Attn: Jon Evans 1045 Reeves Road E. Unit A Bozeman, Montana 59718 Project: Lot 4A – Plat J-33-C Gallatin Park Subdivision Bozeman, Montana CR Project No.: 019119CR Date: November 04th, 2019 Executive Summary Castle Rock Geotechnical has completed this geotechnical engineering report for the above referenced project. Lot 4A is located approximately 725 feet west of the intersection of Manley Road and Gallatin Park Drive. The lot is on the north side of the road. The work was completed for the Client as discussed in a site meeting on October 25, 2019. The geotechnical information provided for an addition to be constructed onto the existing building recommendations is: • Soil Condition • Geo-Hazard Considerations • Groundwater Condition • Earthwork, Foundation Recommendations • Excavated Bore Observations Geotechnical recommendations made within are based upon (3) excavated bores, laboratory-field test results, research, and experience with similar projects. Knowledge of subsurface soils and conditions are limited to the depth of the excavated bores. The bores were excavated down to where groundwater was encountered. • It is concluded that the native sandy aggregate with an occasional boulder at footing grade is suitable for building bearing footing loads following the construction recommendations within the report. If maximum vertical wall and column loads exceed what is assumed please contact our office for additional subgrade improvement recommendations. • Geotechnical recommendations are for subgrade improvements of the Type VB commercial structure with traditional concrete foundations with continuous footing, stem wall, and slab on grade. The improvements will consist of excavation down to proposed footing grade, verifying subsurface soils, properly preparing the newly exposed ground. Geotechnical Investigation Report D:\Jobs File\JBS 2019\019119CR\GI, Lot 4A, Gallatin Park Drive, BZ, MT.doc • All parking lots and drives are to strip the topsoil and loam down to native gravels. Engineered fill or road mix to be properly placed up to parking lot proposed base grade. • If ground conditions are found by the Engineer to not be suitable for the recommendations given within due to some unforeseeable condition, once the site is unearthed additional ground improvements may be required. • Construction activities cannot decrease the stability of the soils at the proposed construction grade. • The Geotechnical Engineer is to verify that the recommendations given within are suitable at the time of development. • All work not observed by the Engineer is inherited by the Contractor. • This Geotechnical Report is to be used by the Client to make educated decisions regarding the development of the site. Castle Rock Geotechnical Engineering is a member of the Geoprofessional Business Association (GBA). Thank you for using Castle Rock Geotechnical Engineering. Sincerely, Andrew Pilskalns, PE Geotechnical Engineer Geotechnical Investigation Report D:\Jobs File\JBS 2019\019119CR\GI, Lot 4A, Gallatin Park Drive, BZ, MT.doc Introduction The work as Castle Rock Geotechnical Engineering (CRGE) understands it is to perform a subsurface, excavated bore geotechnical investigation for the above referenced site at the request of the Client. The recommendations are based on information gained from a site investigation where 3 bores were excavated, laboratory test results obtained, and field observations made. The geotechnical investigation has been performed for the three commercial structures proposed for the site. The existing grounds are near level; grounds sloped from 0% to 3% are termed by the Department of Natural Resources and Conservation Service (DNRC) as ‘near level’. The Legal description is Lot 4A, Northeast ¼ of Southeast ¼, of Section 36, Township 01 South, Range 05 East. Information Shared within this report:  Subsurface soils and their condition  Groundwater and moisture conditions  Geo-related hazards consideration  Earthwork considerations  Subgrade improvement  Seismic classification Ground conditions described should be verified by the Geo-engineer during construction. The Client is responsible for all work and surfaces not observed and verified by the Engineer that prepared this report. Based on the information obtained from the Client it is estimated that the sum of the area of the three buildings’ footprint is approximately 10,000 sqft. If construction assumed is different than planned please contact our office to review and revise the report and recommendations as deemed necessary. Field Observations, Research Andrew Pilskalns P.E. was on site on Monday November 01st, 2019 at 10:00am to direct the excavation and sampling of excavated bore holes at the above referenced site. The purpose of the bore hole investigation is to determine subsurface conditions. Bore 1 is located near the center of proposed Building C. Bore 2 is excavated near the north end of Building A and Bore C is excavated at approximately the south end of Building B. Figure 1, Bore Map, shows the approximate location of the three bores as related to the proposed buildings. Geotechnical Investigation Report D:\Jobs File\JBS 2019\019119CR\GI, Lot 4A, Gallatin Park Drive, BZ, MT.doc Excavate Bore Profile The subsurface profile of all three excavated bores was similar; therefore one description will be given. The surface consists of native grasses and a thin topsoil horizon consisting of brown loam. Figure 1 – Bore Map The topsoil and organics are underlain by a thin layer of brown clay loam, USCS soil classification symbol CL. The clay loam is underlain by native alluvial non-plastic sandy gravels with an occasional 1 foot diameter boulder. Table 1 – Embankment Profiles Horizon Thickness Bore 1 Bore 2 Bore 3 Topsoil 3” 5” 4” Silt Loam 9” 3” 11” Native Pit Run Gravels 5’-4” 5’ 10” 5’-3” Depth to Groundwater 5’-0” 5’-4” 5’-2” Total Depth 6’-4” 6’-6” 6’-6” Geotechnical Investigation Report D:\Jobs File\JBS 2019\019119CR\GI, Lot 4A, Gallatin Park Drive, BZ, MT.doc Note that there are very small differences such as the depth of groundwater and the thickness of the overlying silts. The general profile is given in the Table 1 - Soil Profiles, above. The hydrologic soil group for the clay loam soils is Group B which indicates that the soils have a moderate infiltration rate. The clay loam soils are shallow and over alluvial gravels which have a high infiltration rate. The primary soil with depth is a thin veneer of lean clay, Unified Soil Classification Symbol CL; this is underlain by pit run gravel USCS Symbol, GW or GP. The pit run gravels were not plastic, and cave-in of the embankments was noticed with depth. Department of Natural Resources and Conservation Service The Department of Natural Resources and Conservation Service recorded soil symbol and mapping unit is 457A – Turner Loam, moderately wet, 0 to 2 percent slopes. The soils are derived from alluvium with the landform defined as stream terraces. The NRCS profile shows that clay loams could be as thick as 26 inches; however this is not the case at this site. The clay loam is a very thin veneer and can easily be stripped from the site, stockpiled and used as topsoil or for landscaping. The NRCS considers the soils to be ‘somewhat’ limited for building development due to potential shrink-swell and large stones. The soils are not corrosive to concrete; moderately corrosive to metal. Concrete should be coated for waterproofing and metal should be coated. Linear extensibility of the soils indicates that the soils are given as less than 3 which indicates the soils in the upper 5 feet are not considered highly expansive or overly sensitive to moisture. The alluvium was found to be non-plastic and moderately to well graded sandy gravels. Large boulders were estimated to be 2% of the soil constituents. The Montana Bureau of Mines and Geology Map of Bozeman 30’ x 60’ Quadrangle shows that the site is on the margins of the geologic units Qal – Alluvium (Holocene). Rounded to well- rounded small boulders, cobbles, gravel, sand, silt, and clay, dominantly composed of Archean metamorphic rocks, and dark-colored volcanic rocks, with subordinate Paleozoic limestone, and Precambrian Belt rocks. This information is congruent with the excavated bore data and observations in the field and with the Montana Groundwater Information Center, (GWIC) water well Log No. 280406. In summary the soils at footing grade will be tightly packed hard sand and gravels, sands. This material can be termed soft bedrock. Groundwater and Moisture Condition Geotechnical Investigation Report D:\Jobs File\JBS 2019\019119CR\GI, Lot 4A, Gallatin Park Drive, BZ, MT.doc Groundwater was encountered in all three excavated bore hole. The Montana Groundwater Information Center was researched to determine the static groundwater elevation in the vicinity. Well Log 280406 was used for a groundwater reference since it is in the very near vicinity 317 Gallatin Park Drive and within the same geologic mapping unit. The static water level in the well was 3 feet below top of well casing. The well log stratigraphy recorded 4 feet of topsoil. The topsoil was underlain by 26 feet of gravels and clay underlain by 6 feet of sand and gravels underlain by 20 feet of clay and gravels underlain by ‘hard rock’. Groundwater at footing grade reduces bearing capacity so it is recommended that footing grade should be 2 feet above the high groundwater mark. Near surface moisture, storm water and water absorbed into the ground can have deleterious effects on overall site stability if not adequately prepared for. The soils hydrologic group as determined by the NRCS is Group B. Group B soils have a moderate infiltration rate when thoroughly wet, though the alluvial gravels have a fast infiltration rate. The clay loam soils when wet are poor engineering materials due to low shear strength, friction angle. They should not be used as road fill or structural fill. The site consists chiefly of moderate to well drained soils but high groundwater is present. These subsurface gravel soils have a fast rate of water transmission. • Note, high groundwater will affect effective depth of stormwater discharge systems. French drains are not permitted within 20 feet of any foundation system. • High groundwater prohibits the use of footing drains for standard stem walls; therefore it is recommended that surfaces around the building consist primarily of impermeable surfaces where surface moisture can drain away from the buildings’ foundations, and specifically in locations that do not get direct sunlight. • Stormwater should be discharged a minimum 5 feet from any foundation and discharge cannot flow towards a building’s foundation. Geo-related Hazards The geo-related hazards on site are:  High groundwater  Surface soils with undesirable engineering characteristics.  Near surface water with the potential to flood site. Geotechnical Investigation Report D:\Jobs File\JBS 2019\019119CR\GI, Lot 4A, Gallatin Park Drive, BZ, MT.doc High groundwater is a site constraint that should be taken into account when selecting footing grade and developing the grading plan. This is not a liquefaction, ground stability or groundwater study. To complete such a study requires SPT, “N counts’ with depth to at least 25 feet below grade considering footing width. Based on empirical experience only, we consider the site to have a ‘low to moderate’ potential for Liquefaction primarily due to depth of groundwater and the potential for loose saturated sedimentary horizons to underlie the site. A bore investigation can be completed at the request of the Client to complete a liquidation study. Contact our office to complete a Shallow Foundation Design if desired burial of footing depth is less than minimum prescribed within. Site Preparation Consideration Based on the predominant soil types encountered during the field investigation, construction activities are to adhere to Type C, non-cohesive strength soil conditions, in accordance with OSHA regulations, 2H:1V embankment (See Section F of OSHA Regulations for slopes of wet soils).  Minimal excavation is to be completed of the site; the proposed commercial buildings are to be excavated to footing grade (1 feet above high groundwater which is estimated to be 4 feet below grade).  Only hand tapping compaction tools are to be operated against any foundation wall.  All soft soils are to be removed within the excavated building footprint. The excavated building footprint is the area of the building’s foundation plus three feet beyond on all sides.  The loam spoils from the excavation are to be stockpiled and kept clean of debris and topsoil or garbage. The spoils will be used as non-structural backfill to be placed as landscaping material in maximum 12 inch thick loose lifts.  All soft or yielding soils during compaction of the native ground surfaces and backfill are to be identified and shown to the Engineer, removed and replaced with structural fill then re-compacted.  Once excavated down to firm alluvial gravels, “soft bedrock”, the ground is to be compacted with a minimum Ingersoll-Rand single-smooth drum vibratory compactor minimum 36-inch diameter drum or equivalent. The Engineer is to approve site conditions before construction of ground improvements. Geotechnical Investigation Report D:\Jobs File\JBS 2019\019119CR\GI, Lot 4A, Gallatin Park Drive, BZ, MT.doc  Footing grade should be at an elevation that vibratory compaction does not bring up water to footing grade. Soils that are pumping are to be reported to the engineer immediately and work is to stop immediately.  Footings can be placed directly upon compacted, moisture conditions native non- plastic gravels.  Backfill on the interior of the building is to be imported or approved native Non- Plastic 3 inch minus soils.  The last 6 inches prior to pouring the slab should be 2 inches of ½ inch minus (crusher coarse) underlain by 4 inches of frost free gravel.  A 10 mil water vapor barrier should be placed directly under the slab. Figure 2 – Structural Fill Foundation Design Geotechnical Investigation Report D:\Jobs File\JBS 2019\019119CR\GI, Lot 4A, Gallatin Park Drive, BZ, MT.doc  Backfill is not to be placed until the concrete is properly cured to its 21 day compressive strength.  All backfill fill on the interior and exterior should be placed at the same time to avoid high pressures and cracking of walls.  A heavy mastic water resistant coating is required for all foundation walls.  It is the Client’s responsibility to obtain a Proctor (w/Oversize correction) of the native gravels and a 3rd Party Tester (Western Materials and Testing) to have non- destructive nuclear gauge testing completed on all compacted native alluvial gravel soils to determine that they are compacted to the soil’s maximum dry density and +3% of the soil’s optimum moisture content as prescribed by ASTM D-698. In addition, imported structural fill is also to be tested in the same manner. Compaction Requirements are given within this report.  Testing results are to be shared with “in place” density and moisture tests and approved by the Engineer or certified tester.  The interior of excavated building footprints are to be backfilled with approved imported structural fill up to 4 inches below slab grade. Twelve-inch thick loose lifts of structural fill will be placed to bring up the ground to footing grade.  Imported structural fill will be used, which will be defined as processed 3-inch minus pit run gravels containing less than 10% non-plastic fines. Pumping of structural fill is not to occur. All soft areas that deflect during compaction of the native structural fill are to be identified, reworked, and approved by the engineer. The subgrade improvements will act as a stiff platform on which the building loads will be supported.  The logical direction to gravity drain surface and near surface flows and the footing drain is to the northwest in the wetlands. All stormwater flow is to be hard piped to the designated stormwater area and discharge on an armored pad to prevent erosion.  Storm drain pipe is to be sloped so that the drain laterals can gravity flow water to the northwest of the site and discharge stormwater area. Geotechnical Investigation Report D:\Jobs File\JBS 2019\019119CR\GI, Lot 4A, Gallatin Park Drive, BZ, MT.doc  To achieve proper grading around the building after the exterior walls have been backfilled, native soils or imported non-expansive lean clay approved by the engineer can be placed, moisture conditioned, and compacted to 95% of the materials maximum dry density. The Client will be responsible for obtaining Proctors and compaction tests for soils placed as fill. If soil characteristics change, new Proctors will be required.  It is also recommended that all areas such as drives, patios, and walkways be over excavated, removing all topsoil and lean clays, compacted and backfill up to the desired grade with engineered fill (utilizing the same compaction equipment recommended above).  It is recommended that the finished floor elevation be such that all sides of the building have positive drainage. Positive drainage is defined as grounds sloped 5% for the first 10 feet on all sides of the building to prevent flooding of the foundation.  No water is to be allowed to pond within the first 15 feet of the building. All backfill is to be free of topsoil and garbage or rejected undesirable soils; approved native soils may be used and placed after the installation of the footing drain. No gravels greater than 4 inches in diameter are to be placed around the building as backfill.  Backfill against concrete walls should only take place after they have cured and are strong, 80% of the concrete’s 28 day compressive strength. Hand tapping tools are recommended for compaction of backfill against foundation walls. No fill should be placed against weak, green walls that are not properly cured. The subgrade improvements for footings apply to all piers, columns, and critical slabs and features such as attached porches, etc. Foundation Size Minimum footing depth and width recommended is 8 x 18 inches respectively for either a single or two-level facility. The bottom of footing as required by Montana State Code is to be protected by 4 feet of cover for 2 story buildings, 36 inches for single-story building.  The allowable bearing capacity for the native sandy soils with some fines with the subgrade improvements implemented is 2,500 lbs/ft² on the footing size dimensioned above. It is anticipated that total settlement of foundations designed and placed as recommended above will be less than 1 inch under the assumed loads. Geotechnical Investigation Report D:\Jobs File\JBS 2019\019119CR\GI, Lot 4A, Gallatin Park Drive, BZ, MT.doc  For the native, processed, 3-inch minus pit run gravels, the effective stress friction angle is 38◦. The Sub-grade Modulus for imported on-site 3-inch minus, USCS symbol, GW engineered-structural fill placed to the soils optimum moisture and dry density is 350 psi/in. Lateral Load Resistance: Foundation footing drains are to be installed to reduce hydrostatic pressure on any wall or retaining wall taller than 6 feet. All foundation walls are assumed to be fixed at the top. Both the passive and frictional resistance of the foundation can be assumed to act concurrently. Active earth pressure design assumes movement of the wall, where as “at rest” design assumes no movement. The Structural Engineer may neglect the weight of the foundation and backfill when determining dead loads. When calculating resistance to vertical dead loads the coefficient of friction of the soil aggregate mixture upon which the foundation is constructed upon is 0.46, with a passive equivalent fluid pressure of 335 pcf. For short-period loading from wind or seismic loads, allowable bearing pressures may be increased by one-quarter. Friction angle used for poorly graded gravel sand is 38◦. Lateral Earth Pressures coefficients for Cohesionless granular Coarse Sand: (1) The active, Ka - 0.30 and an equivalent fluid pressure is 60 pcf. (2) The passive, Kp – 3.3. (3) At rest, Ko - .46 and an equivalent fluid pressure of 51 pcf. (Non-sloped condition) Lateral Earth pressures coefficients for Structural fill. (1) The active, Ka - 0.27 and an equivalent fluid pressure is 42 pcf. (2) The passive, Kp – 3.5 (3) At rest, Ko - .46 and an equivalent fluid pressure of 65 pcf. Lateral Earth pressure coefficients for backfill are to be taken for the processed native soils. The lateral earth pressures recommended do not include a factor of safety against the pressures caused by hydrostatic forces.  Unit weights of native silt soils are given as 110 lbs/ft³.  Unit weights of 1 inch diam. gravel or structural fill are given as 140 lbs/ft³.  Add seismic thrust as prescribed in the International Building Code (IBC).  Assume all walls are drained as recommended and no hydrostatic pressures are acting on the wall. Geotechnical Investigation Report D:\Jobs File\JBS 2019\019119CR\GI, Lot 4A, Gallatin Park Drive, BZ, MT.doc  All concrete walls are to have 90% of their 28 day compressive strength prior to backfill.  Use hand tapping tools to compact all backfill. No consideration for heavy compaction equipment.  Assumes no clay or expansive soils will be used as backfill next to a wall.  Assumes native backfill is placed at an angle of 55 degrees from the base of the wall outward away from the wall.  Assumes horizontal ground surface for the first 25 feet away from the foundation wall. Compaction Requirements Utilizing Army Corp of Engineering test results it has been proven that the required density of fill can be achieved (100% maximum dry density) if the pit run type material is placed in 6-inch lifts, track packed then compacted by a smooth drum vibratory roller (minimum 6 passes) with the vibratory equipment operating between 1-2 mile/hour. TABLE 2 – COMPACTION REQUIRMENTS APPLICATION PERCENT COMPACTION Wall Backfill 95 Structural Fill Under Slab 95 Structural Fill Under Footing 98 One pass is considered across the site and back to its original starting position. This type of compaction method should be used on all placed fill at recommended lift thickness with the compactor operating as mentioned above. Depth of fill will vary slightly across the excavated site. Density testing of fills and backfills placed beneath footings, slabs, and pavement is recommended. Density tests are to be performed on foundation wall backfill. All density tests are to be completed with certified Troxler 3411-B nuclear gauges with 8-inch rod or equivalent. It is recommended that slump, temperature, air content, and strength tests on Portland cement concrete be performed. Samples of proposed backfill and fill materials should be submitted to testing laboratory at least 5 days prior to placement on the site for evaluation and determination of their optimum moisture contents and maximum dry densities. All backfill placed that is not tested is inherited by the Owner and or Contractor. Geotechnical Investigation Report D:\Jobs File\JBS 2019\019119CR\GI, Lot 4A, Gallatin Park Drive, BZ, MT.doc Backfill  It is recommended that approved imported structural fill be compacted in 12 inch loose lifts to a minimum of 98 percent of its Standard Proctor (ASTM D-698) maximum dry density.  It is recommended that native soils used as backfill against walls be compacted in 12 inch loose lifts to a minimum of 95 percent of its Standard Proctor (ASTM D-698) maximum dry density.  No self-propelled compaction equipment must operate within 2-ft of concrete walls. Backfill on the outside of the wall is to occur at the same time as backfill is placed on the interior, neither exceeding the other in height by 1 foot. The Contractor is responsible for good construction practices such as protecting the subsurface soils on which the foundation rests at all times from excessive moisture or freezing temperatures. At no time are the footings to be built on saturated or frozen soils. At no time are wet or frozen materials to be used as fill.  All fill placed around the building is to be compacted to 95% of the materials optimum dry density to prevent the easy absorption of moisture into the ground around the foundation. Impermeable soils are to be used as finished cover (backfill) prior to the placement of topsoil.  The foundation is to be protected from heaving due to freezing temperatures or excessive snow/rain until backfill is placed.  No backfill is to be placed on organics such as grass, or on snow/ice, or water. Impermeable soils should be used as finished cover (backfill) prior to the placement of topsoil to prevent the easy absorption of precipitation around the building. No surface is to allow water to pond within 20-ft of the building. Seismic Consideration Based on the results of our sub-surface investigation and review of available geologic information, we anticipate the upper 50 foot profile will be comprised of sedimentary deposits of stiff and soft silt, sand, clays, gravels, or similar underlain by hard bedrock. Therefore, we recommend using Site Class "D" (stiff soil profile) as defined by the 2012 International Building Code (2012 IBC) for design. Geotechnical Investigation Report D:\Jobs File\JBS 2019\019119CR\GI, Lot 4A, Gallatin Park Drive, BZ, MT.doc Seismic calculations are made in accordance to general procedures as used/defined by the United State Geological Survey (USGS), American Society of Civil Engineers Chapter 7, (ASCE 7) and 2012 IBC. Conclusion This report is for the exclusive use of the Client, and Castle Rock Geotechnical Engineering, to use to design the proposed structure and prepare construction documents. In the absence of our written approval, we make no representation and assume no responsibility to other parties regarding this report. The recommendations are only for this property. Castle Rock Geotechnical Engineering cannot assume responsibility or liability for any of the recommendations within, subgrade conditions, materials used, and construction work, or performance of materials that are not observed, and recorded by the Engineer that prepared this report. The recommendations, if adhered to, are adequate for supporting the commercial building loads given above. If you have any questions or concerns about the contents of this letter please contact me at your convenience. Services performed by Castle Rock Geotechnical Engineering for this project have been conducted with that level of care and skill ordinarily exercised by members of the profession currently practicing in this area under similar budget and time constraints. The successful completion of the geotechnical engineering of this project is dependent on continued professional geotechnical services to ensure the proper interpretation and intentions of the recommendations herein and to observe the construction phases of the design (earthwork, foundation, site grading). Castle Rock Geotechnical Engineering is not responsible for quality of “Others” work or interpretation of the recommendations. Furthermore no warranty, expressed or implied, is made. Castle Rock Geotechnical is a member of the Geoprofessional Business Association (GBA). To better understand how geotechnical reports are to be interpreted please read Important Information about Your Geotechnical Report provided by GBA found in the Attachments. This report is time dependent; if construction does not occur within 1 year of the date this report was prepared it is recommended that the project be reviewed again by a Professional Geotechnical Engineer. Revisions may be necessary due to changes in site conditions and/or in Geotechnial techniques and methods. Geotechnical Investigation Report D:\Jobs File\JBS 2019\019119CR\GI, Lot 4A, Gallatin Park Drive, BZ, MT.doc I hereby certify this report was prepared by me and that I am a duly licensed Professional Engineer under the laws of the State of Montana. I appreciate the opportunity to work with you. Prepared By: Andrew Pilskalns, P.E., M.ASCE, M.GBA Civil Engineer LICENSED – Montana, Utah, Colorado, Hawaii, Nevada, North Dakota, Wyoming CASTLE ROCK GEOTECHNICAL ENGINEERING INC. 9 Cedar Lake Drive Butte, MONTANA 59701 C: (406) 539-8439 O: (406) 209-5573 www.castlerocker.com andy@castlerocker.com ap.castlerock@gmail.com ATTACHMENTS Definitions Important Information about Your Geotechnical Engineering Report Geotechnical Investigation Report D:\Jobs File\JBS 2019\019119CR\GI, Lot 4A, Gallatin Park Drive, BZ, MT.doc ATTACHMENTS Definitions To assist the reader in understanding site conditions at a point in time, several definitions have been prepared. The terms include pre-development, development, and post-development grades. Other important terms and definitions are listed below. Unified Soil Classification System (USCS): USCS is a soil classification system used in engineering and geology to describe the texture and grain size of soils. Soil: a sediment or other accumulation of mineral particles produced by the physical or chemical disintegration of rock, plus the air, water, organic matter, and other substances that may be included. Soils are a foundation material upon which structures bear. Overburden/Spoils: Soils that are disturbed by construction activities; including soils that have been placed upon undisturbed ground surfaces. Examples for this site are soils consisting of dark brown silt loam with organics, dark brown sandy gravels, mottled silt, clay loam, and non-plastic sandy gravels. Topsoil: Native soil material consisting of dark brown silt loam with a high amount of organics; usually undisturbed ground’s first soil horizon. Topsoil remnants have been observed under spoils across the property. Lot subgrade improvements: Geotechnical recommendations given regarding the development of each commercial building proposed for the lot for the benefit of the Builder. Structural Fill: Soil upon which structural elements such as footings, sonotubes, slabs, etc. may be constructed upon. Two different types of material may be used as structural fill: imported 3-inch minus (well graded) pit run gravels with less than 10% non-plastic fines as described in Table 3 of this report, or 1 inch diameter washed rock. Other types of gravels and sand mixtures, USCS soil classification symbol – GP or GW may be used as approved structural fill if approved by the GeoEngineer upon request. Building Footprint: The entire heated area of the house including covered porches. Road Footprint: width and length of subbase and aggregate footprint (extend a minimum one foot horizontally beyond curb and gutter) for city rural and collector roads as defined by MPW road sections. Soil Pumping: Movement of soils under load due to excess pore water pressure in the soils. Excavation footprint: The building footprint plus an additional 3-feet horizontal around the perimeter of the building footprint. Settlement: is the result of consolidation of soils. Subsidence: is the sudden sinking of soils or gradual downward settlement with little or no horizontal movement.