4. Road Deformation Due to a Problem Tree
On steep terrain, trees typically lean due to soil movement. In the case of the photo on the right, road construction above the tree could have destabilized the hillside, or the soils under the tree could have been slowly sliding over time. For whatever reason, the stump, which is located partially under the road, is rotating and moving within the road subgrade. The result has been severe road deformation and alligatoring. In addition, road runoff has been flowing down the road and entering the roadway through the fractured pavement. Acting as a lubricant, the water is weakening the subgrade while working to destabilize the tree root system. Ultimately, if this situation is not addressed, catastrophic failure will occur as both the tree and part of the road will break away and slide down the hillside.
The Fix: Immediately remove the tree at the stump. Once this “lever” has been removed, the road should be excavated and filled in the same fashion as described above in how to fix a pothole. Whether or not the stump should be removed largely depends on where it is and how big it is. If removing the stump also means removing a significant portion of the slope itself, you may need to determine the cost and benefits of performing such work.
Otherwise, you may find yourself building a retaining wall just to reestablish the road. If the stump is isolated within the road and can easily be removed, it should be replaced with crushed rock or free-draining structural import material. Quality free-draining fill material can be located at local pits and hauled in to your jobsite.
Rod Johnston, author of “Road Repair Handbook” as well as “Preparing Projects for Site Construction,” resides in North Carolina where he works as a land development and project management consultant.
On steep terrain, trees typically lean due to soil movement. In the case of the photo on the right, road construction above the tree could have destabilized the hillside, or the soils under the tree could have been slowly sliding over time. For whatever reason, the stump, which is located partially under the road, is rotating and moving within the road subgrade. The result has been severe road deformation and alligatoring. In addition, road runoff has been flowing down the road and entering the roadway through the fractured pavement. Acting as a lubricant, the water is weakening the subgrade while working to destabilize the tree root system. Ultimately, if this situation is not addressed, catastrophic failure will occur as both the tree and part of the road will break away and slide down the hillside.
The Fix: Immediately remove the tree at the stump. Once this “lever” has been removed, the road should be excavated and filled in the same fashion as described above in how to fix a pothole. Whether or not the stump should be removed largely depends on where it is and how big it is. If removing the stump also means removing a significant portion of the slope itself, you may need to determine the cost and benefits of performing such work.
Otherwise, you may find yourself building a retaining wall just to reestablish the road. If the stump is isolated within the road and can easily be removed, it should be replaced with crushed rock or free-draining structural import material. Quality free-draining fill material can be located at local pits and hauled in to your jobsite.
Rod Johnston, author of “Road Repair Handbook” as well as “Preparing Projects for Site Construction,” resides in North Carolina where he works as a land development and project management consultant.
The joys of living in cabin country are often overshadowed by the hassle of dealing with poor road and driveway conditions. Potholes that jolt you out of your seat, road sections that threaten to break away and take you with them down to the lake, and pavement that resembles a parking lot under demolition – these problems can both damage your car and keep you from comfortably reaching your coveted destination, your cabin. Let’s look at a few issues common to rural roads and driveways and explore why they happen and what you can do about them.
1. Bad Grading, Bad Driveway
Improper road grading damages driveways and roads. There’s no way around it. Blading off expensive crushed rock, not maintaining ditches, and shaping a road surface to collect, rather than disperse water, will all eventually work to degrade that road.
In these photos, look at the ditch line (the border between the road and the ditch). “What ditch line?” you might ask, and rightly so. The ditchline has been filled by erosion and road debris. Once a ditchline fills and drivers lose respect for it, they will begin traveling in it, one wheel at a time. This effectively turns the ditch into part of the road. Without a ditch, water that is shed from the road surface has no place to flow except down the road. Free-flowing water cuts channels into dirt road surfaces causing the road to soften and become irregular. Small holes become large holes and soft water-saturated areas grow into deep water-collecting potholes.
The Fix: Grade your driveway or road so that it sheds water onto the shoulder, or into a ditch, and away from all lanes of traffic.
Also observe the line of crushed rock that has been bladed to the road edge. This rock belongs on the road, not on the shoulder. All dirt roads should be graded by “pulling” loose edge material and rock to the road center before re-blading it evenly onto the running surface. When good rock surfacing is graded off the road center, the likelihood of exposing native material (silts and clays) increases. Somebody paid good money to have crushed rock brought in for the very purpose of covering native soils while creating a stable roadway. Undoing this investment works to waste money and ruin the road.
A third element missing from these photos is any hint of where the road slopes to shed water. Note that this is a steep road. The road must be sloped one way or the other, or crowned, to prevent water from running down the center of the road to the pavement below. The fix here is to hire a contractor to re-channel the ditch, shape the road so that it sheds water, and then pull all shoulder rock back onto the road for surfacing. Of course the road would also benefit from having a few loads of new crushed rock hauled in and graded onto the road. If the owners can afford it, a final suggestion would be to hire a roller to compact all crushed rock into the roadbed. This would provide stability while decreasing the chance of having loose rock thrown aside by the tires of traveling vehicles.
Improper road grading damages driveways and roads. There’s no way around it. Blading off expensive crushed rock, not maintaining ditches, and shaping a road surface to collect, rather than disperse water, will all eventually work to degrade that road.
In these photos, look at the ditch line (the border between the road and the ditch). “What ditch line?” you might ask, and rightly so. The ditchline has been filled by erosion and road debris. Once a ditchline fills and drivers lose respect for it, they will begin traveling in it, one wheel at a time. This effectively turns the ditch into part of the road. Without a ditch, water that is shed from the road surface has no place to flow except down the road. Free-flowing water cuts channels into dirt road surfaces causing the road to soften and become irregular. Small holes become large holes and soft water-saturated areas grow into deep water-collecting potholes.
The Fix: Grade your driveway or road so that it sheds water onto the shoulder, or into a ditch, and away from all lanes of traffic.
Also observe the line of crushed rock that has been bladed to the road edge. This rock belongs on the road, not on the shoulder. All dirt roads should be graded by “pulling” loose edge material and rock to the road center before re-blading it evenly onto the running surface. When good rock surfacing is graded off the road center, the likelihood of exposing native material (silts and clays) increases. Somebody paid good money to have crushed rock brought in for the very purpose of covering native soils while creating a stable roadway. Undoing this investment works to waste money and ruin the road.
A third element missing from these photos is any hint of where the road slopes to shed water. Note that this is a steep road. The road must be sloped one way or the other, or crowned, to prevent water from running down the center of the road to the pavement below. The fix here is to hire a contractor to re-channel the ditch, shape the road so that it sheds water, and then pull all shoulder rock back onto the road for surfacing. Of course the road would also benefit from having a few loads of new crushed rock hauled in and graded onto the road. If the owners can afford it, a final suggestion would be to hire a roller to compact all crushed rock into the roadbed. This would provide stability while decreasing the chance of having loose rock thrown aside by the tires of traveling vehicles.
2. Edge Damage
Damaged or failed asphalt along the road’s outer edge is a common condition on narrow roads where vehicles continually travel on and off the road edge to avoid hikers, bicyclists or horses. Edge damage also occurs along inner road curves. Here, the rear wheels of vehicles usually drift or “track” deeper into the curve than the front tires and directly over the edge of asphalt. Vehicles towing trailers will further erode the pavement edge since trailers will always migrate deeper into a curve, and sometimes off the pavement and onto the dirt shoulder, thereby stressing and potentially damaging the asphalt edge. The edges of most asphalt roads can survive occasional abuse, however a road that is built too narrow, especially at curves, invites eventual tire damage.
The Fix: Increase the road width in curved areas. This can be accomplished by widening with pavement or by adding a course of crushed rock laid even with the road surface.
Damaged or failed asphalt along the road’s outer edge is a common condition on narrow roads where vehicles continually travel on and off the road edge to avoid hikers, bicyclists or horses. Edge damage also occurs along inner road curves. Here, the rear wheels of vehicles usually drift or “track” deeper into the curve than the front tires and directly over the edge of asphalt. Vehicles towing trailers will further erode the pavement edge since trailers will always migrate deeper into a curve, and sometimes off the pavement and onto the dirt shoulder, thereby stressing and potentially damaging the asphalt edge. The edges of most asphalt roads can survive occasional abuse, however a road that is built too narrow, especially at curves, invites eventual tire damage.
The Fix: Increase the road width in curved areas. This can be accomplished by widening with pavement or by adding a course of crushed rock laid even with the road surface.
3. Asphalt Pothole
Potholes usually develop when a road’s subgrade has been weakened or stressed. Though many private roads have been constructed with a quality crushed rock subgrade, most private roads consist of native dirt material. Once graded, pavement is laid and the road is complete. Subgrade failures occur for many reasons. Organic materials, such as stumps and topsoil, decay and cavitate resulting in road deformation and eventual low areas, which leads to potholes. Moisture – due to improper ditching, a failure to shed surface runoff, or subsurface water migration – can enter and weaken a road subgrade. In some cases, poor construction and lack of compaction results in early failure.
The Fix: Potholes are best repaired by first determining if water is causing the soils to weaken. If water is determined to be a cause, inspect your ditches and determine whether or not they need to be reshaped, excavated deeper or channeled for better drainage. Then excavate the pothole. Sawcut paved areas at least a foot or so beyond the pothole limit. (Try to avoid removing, or breaking, any pavement out in a jagged manner.) After removing the pavement, excavate the pothole deep enough to remove wet and weak soils, or at least two feet of soil. Replace all removed soil with crushed rock. Patch paved areas and seal the edges. Also, evaluate the speed and size of vehicles that travel your roadway. It might be time to erect signs and post weight limits.
Potholes usually develop when a road’s subgrade has been weakened or stressed. Though many private roads have been constructed with a quality crushed rock subgrade, most private roads consist of native dirt material. Once graded, pavement is laid and the road is complete. Subgrade failures occur for many reasons. Organic materials, such as stumps and topsoil, decay and cavitate resulting in road deformation and eventual low areas, which leads to potholes. Moisture – due to improper ditching, a failure to shed surface runoff, or subsurface water migration – can enter and weaken a road subgrade. In some cases, poor construction and lack of compaction results in early failure.
The Fix: Potholes are best repaired by first determining if water is causing the soils to weaken. If water is determined to be a cause, inspect your ditches and determine whether or not they need to be reshaped, excavated deeper or channeled for better drainage. Then excavate the pothole. Sawcut paved areas at least a foot or so beyond the pothole limit. (Try to avoid removing, or breaking, any pavement out in a jagged manner.) After removing the pavement, excavate the pothole deep enough to remove wet and weak soils, or at least two feet of soil. Replace all removed soil with crushed rock. Patch paved areas and seal the edges. Also, evaluate the speed and size of vehicles that travel your roadway. It might be time to erect signs and post weight limits.
Road Deformation Due to a Problem Tree
On steep terrain, trees typically lean due to soil movement. In the case of the photo on the right, road construction above the tree could have destabilized the hillside, or the soils under the tree could have been slowly sliding over time. For whatever reason, the stump, which is located partially under the road, is rotating and moving within the road subgrade. The result has been severe road deformation and alligatoring. In addition, road runoff has been flowing down the road and entering the roadway through the fractured pavement. Acting as a lubricant, the water is weakening the subgrade while working to destabilize the tree root system. Ultimately, if this situation is not addressed, catastrophic failure will occur as both the tree and part of the road will break away and slide down the hillside.
The Fix: Immediately remove the tree at the stump. Once this “lever” has been removed, the road should be excavated and filled in the same fashion as described above in how to fix a pothole. Whether or not the stump should be removed largely depends on where it is and how big it is. If removing the stump also means removing a significant portion of the slope itself, you may need to determine the cost and benefits of performing such work.
Otherwise, you may find yourself building a retaining wall just to reestablish the road. If the stump is isolated within the road and can easily be removed, it should be replaced with crushed rock or free-draining structural import material. Quality free-draining fill material can be located at local pits and hauled in to your jobsite.
Rod Johnston, author of “Road Repair Handbook” as well as “Preparing Projects for Site Construction,” resides in North Carolina where he works as a land development and project management consultant.
On steep terrain, trees typically lean due to soil movement. In the case of the photo on the right, road construction above the tree could have destabilized the hillside, or the soils under the tree could have been slowly sliding over time. For whatever reason, the stump, which is located partially under the road, is rotating and moving within the road subgrade. The result has been severe road deformation and alligatoring. In addition, road runoff has been flowing down the road and entering the roadway through the fractured pavement. Acting as a lubricant, the water is weakening the subgrade while working to destabilize the tree root system. Ultimately, if this situation is not addressed, catastrophic failure will occur as both the tree and part of the road will break away and slide down the hillside.
The Fix: Immediately remove the tree at the stump. Once this “lever” has been removed, the road should be excavated and filled in the same fashion as described above in how to fix a pothole. Whether or not the stump should be removed largely depends on where it is and how big it is. If removing the stump also means removing a significant portion of the slope itself, you may need to determine the cost and benefits of performing such work.
Otherwise, you may find yourself building a retaining wall just to reestablish the road. If the stump is isolated within the road and can easily be removed, it should be replaced with crushed rock or free-draining structural import material. Quality free-draining fill material can be located at local pits and hauled in to your jobsite.
Rod Johnston, author of “Road Repair Handbook” as well as “Preparing Projects for Site Construction,” resides in North Carolina where he works as a land development and project management consultant.
© Anatoli Styf 
Thinkstock.com 
Rod Johnston 
© Anatoli Styf 
None
Cabin Porn: Inside
None
Winter Outdoor Faucet Cover
