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Project Manual <br />Houlton Conservation Area Bank Stabilization — Dam Site <br />DIVISION 02 <br />CONSTRUCTION SPECIFICATIONS <br />Minnesota Department of Transportation Standard Specifications for Construction (2020 edition) shall <br />apply for all materials and construction work unless superseded by the following special provisions. <br />S-1 (2577) SOIL BIOENGINEERED SYSTEMS <br />MnDOT 2577 is supplemented with the following: <br />5-1.1 DESCRIPTION <br />This work consists of installing a bioengineered system consisting of a toewood bench for river <br />bank stabilization. <br />5-1.1 MATERIALS <br />The toewood bench shall include the following materials: <br />A. Geosythetic Materials ........................................................................................................ 3733 <br />B. Sod ......................................................................................................................................3878 <br />C. Rolled Erosion Prevention Product ....................................................................................3885 <br />5-1.2 CONSTRUCTION REQUIREMENTS <br />Construct Toewood Bench consisting of a series of rootwads, footer and face logs, and anchoring <br />systems covered in layers of woody debris, common embankment (soil backfill), fabric <br />encapsulated soil lifts, and sod mats according to the plans. <br />Support root wads with footer logs shall be a minimum 12 inches in diameter with limbs removed <br />and minimum 10 feet in length. Space footer logs approximately 8 to 10 feet apart perpendicular <br />to the rootwads (slightly off parallel to the bank). Partially embed and key footer logs into existing <br />bank material. <br />Rootwads shall be assembled from a large tree trunk with a minimum diameter of 12 inches with <br />limbs removed and length of 14 to 20 feet with attached roots. Place rootwads on top of footer <br />logs as shown overhanging rootwads 1 to 2 feet protruding into the river angled at about 30 <br />degrees from perpendicular to the bank with the rootwads facing upstream. Rootwads shall be <br />spaced such that the outer diameters of the attached roots appear to be touching or slightly <br />overlapping when viewed from an angle parallel to the bank and direction of flow. Place face logs <br />similar dimensions to the footer logs at similar angles to the footer logs on top of the rootwad <br />trunk. <br />Place woody debris comprised of 75% small limbs and branches (3 inch minus) and 25% medium <br />sized material (3 to 6 inch limbs) between the rootwads, footer and face logs. Layer and compact <br />common embankment (soil backfill) in the void space of the woody debris. Place Type 3 geotextile <br />per 3733, "Geosynthetic Materials," over the backfill material. <br />Division 02 SP-1 <br />Construction Specifications Special Provisions <br />