Vegetated Geogrids

Live Stakes / JointPlantingApproachConstruction CostSoft Hard Low HighMaintenance CostAdaptabilityLow High Low HighDescriptionJoint Planting consists of adding livestakes or vegetation into open spaces orjoints in an already existing rip rap orrock covered slope. Alternatively, thestakes can also be placed at the sametime as the rock reinforcement. Whenthe system of roots from the live stakesdevelops it creates a living root matbeneath the rocks, binding the soil andpreventing washout of the soil and finematerial.Figure 27: Typical joint planting.Design and ConstructionVery little information is available onthe design of joint plantings. Jointplantings are typically constructed inareas where a sloping rip-rap or rockrevetment either exists or is planned.Live stakes/joint planting should beconsidered only if the accompanyingstructure will be subject to minor waveaction. This method should be used onstreams with minimal flow fluctuations.The site should have a moderate slope,and sufficient lighting available for theplants to grow. Permissible shearstresses of 2.1 lb/sf - 3.1 lb/sf and flowvelocities of 3 ft/sec – 10 ft/sec are givenfor live willow stakes in Fischenrich(2001).Construction materials for a jointplanting project consist of 2” to 3”diameter live stakes (willow or otherwoody plants), and appropriately sizedrocks if an accompanying rock structureis to be built. The live stakes are placedperpendicular to the slope and tampedtwo thirds of their length into theground. A steel rod or hydraulic probemay be required to prepare the hole forthe planting. The joint plantings shouldbe left with their tips slightly protrudingfrom the surface of the rocks and placedin a random configuration. Afterconstruction there is typically littlemaintenance involved.DRAFTThe capitol cost of joint planting is lowcompared to other methods, particularlyif the rock covered slope already exists.Prices normally range from $1/sf - $5/sf.If additional site work is needed, thesecosts can rise to more than $35/sf.