HMROSS
Civil/Environmental
- Aug 12, 2003
- 11
ROCKERY WALL DESIGN
Objective: Local Public Works Department (PWD) has asked for design documentation for a proposed ROCKERY WALL as part of the single family dwelling (SFD) project. The wall is not part of the residential structure. The plans and structural package for the SFD were submitted and approved with no comments and/or corrections. The project requires a grading permit under the PWD and they are requiring a structural design report. I have a geotechnical report for the site. Yes, I could design a concrete and/or reinforced CMU retaining wall as used for the house design but I want the aesthetics provided by the rocks on the outside. There is a fairly close limestone source with 500 lb to 2 ton boulders (24” to 60”) and 75 to 1-1/2 ton boulders (10” to 36”), and smaller rock of course.
I do not want to re-create the wheel--nor spin the wheels I do have. I need a standard-of-practice design rational with practical applications for a Rockery Wall of moderate height, above 6 feet below 16 feet. This wall is 9-feet at its maximum and about 45 feet long. There is approximately 6 to 7 feet of native soil, the remaining soil will come from the house excavation (fill). The lower 4 feet of the wall will be against undisturbed weathered/fractured rock of good stability. The remaining five feet will have to be dealt with in the design.
Maybe one of you guys or gals can say with some degree of certainty what the design rational should be to prepare a design report for submittal: My draft:
1. Geometry (completed)
2. Site Conditions and Soil Properties (completed)
3. Rockery Material Properties—(can get, may need something—not sure at this time)
4. Mass Calculations—(an example for Rockery Wall would be nice to have just for comfort)
5. Overturning & Sliding—(I need a realistic approach to interaction between the soil active/passive forces and seismic induced forces—an example would be great with assumptions in regards to values and safety factors applied.)
Well, Do I need all these things, or not, and/or more?
It seems if I take the necessary precautions in design and possibly reinforce the top soil layers I can do this wall without much problem.
Additionally—I have done my home work on this forum—it’s a good forum.
I have read the following threads as found under the search through this forum for “ROCKERY” Thead255-82018, Thead255-86678, Thead255-71439, & Thead255-66400. Paragraphs below in quotes are from the above threads.
Prescriptive design standards in various location across the west allow for up to a 6-foot high wall with proper soil conditions. The Department of Planning and Development at the City of Seattle, document CAM 21, Rockeries: Prescriptive Design and Installation Standards is very good for this type of wall. However, if say two-feet of fill is placed behind the wall, the permitting agency will most likely want a structural analyses of some level.
I have ordered a copy of the Rock Wall Construction Guidelines,” by the Associated Rockery Contractors, August 15, 2000 edition. This should cover much of what I need; however, I fear it will not include a rational design process.
Does anybody have a copy of the Design Manual for Segmental Retaining Walls published by the National Concrete Masonry Association? Does this publication handle Rockery Wall Structural Design to the current standard-of-practice. The forum thread said the “Outlined in the manual is both gravity and geosynthetic reinforced walls.”
“Most important is the character of the stone facing the viewpoint. The "chi" of the stone, and its particular placement will establish a long lasting structure and pleasant view.”
I am not worried about the “chi” but I will include this statement for the local County Engineer, maybe he is?
“US Department of Agriculture - Forest Service EM-7170-14 or FHWA-FLP-94-006 1-202-205-0820. Once this organization went defunct a large rockery builder took it over based out of the Seattle are and a few years ago was still passing out this manual 1-425-481-3456.”
Does anyone have the EM-7170-14 or FHWA-FLP-94-006 1-202-205-0820?
I have to sleep now.
Objective: Local Public Works Department (PWD) has asked for design documentation for a proposed ROCKERY WALL as part of the single family dwelling (SFD) project. The wall is not part of the residential structure. The plans and structural package for the SFD were submitted and approved with no comments and/or corrections. The project requires a grading permit under the PWD and they are requiring a structural design report. I have a geotechnical report for the site. Yes, I could design a concrete and/or reinforced CMU retaining wall as used for the house design but I want the aesthetics provided by the rocks on the outside. There is a fairly close limestone source with 500 lb to 2 ton boulders (24” to 60”) and 75 to 1-1/2 ton boulders (10” to 36”), and smaller rock of course.
I do not want to re-create the wheel--nor spin the wheels I do have. I need a standard-of-practice design rational with practical applications for a Rockery Wall of moderate height, above 6 feet below 16 feet. This wall is 9-feet at its maximum and about 45 feet long. There is approximately 6 to 7 feet of native soil, the remaining soil will come from the house excavation (fill). The lower 4 feet of the wall will be against undisturbed weathered/fractured rock of good stability. The remaining five feet will have to be dealt with in the design.
Maybe one of you guys or gals can say with some degree of certainty what the design rational should be to prepare a design report for submittal: My draft:
1. Geometry (completed)
2. Site Conditions and Soil Properties (completed)
3. Rockery Material Properties—(can get, may need something—not sure at this time)
4. Mass Calculations—(an example for Rockery Wall would be nice to have just for comfort)
5. Overturning & Sliding—(I need a realistic approach to interaction between the soil active/passive forces and seismic induced forces—an example would be great with assumptions in regards to values and safety factors applied.)
Well, Do I need all these things, or not, and/or more?
It seems if I take the necessary precautions in design and possibly reinforce the top soil layers I can do this wall without much problem.
Additionally—I have done my home work on this forum—it’s a good forum.
I have read the following threads as found under the search through this forum for “ROCKERY” Thead255-82018, Thead255-86678, Thead255-71439, & Thead255-66400. Paragraphs below in quotes are from the above threads.
Prescriptive design standards in various location across the west allow for up to a 6-foot high wall with proper soil conditions. The Department of Planning and Development at the City of Seattle, document CAM 21, Rockeries: Prescriptive Design and Installation Standards is very good for this type of wall. However, if say two-feet of fill is placed behind the wall, the permitting agency will most likely want a structural analyses of some level.
I have ordered a copy of the Rock Wall Construction Guidelines,” by the Associated Rockery Contractors, August 15, 2000 edition. This should cover much of what I need; however, I fear it will not include a rational design process.
Does anybody have a copy of the Design Manual for Segmental Retaining Walls published by the National Concrete Masonry Association? Does this publication handle Rockery Wall Structural Design to the current standard-of-practice. The forum thread said the “Outlined in the manual is both gravity and geosynthetic reinforced walls.”
“Most important is the character of the stone facing the viewpoint. The "chi" of the stone, and its particular placement will establish a long lasting structure and pleasant view.”
I am not worried about the “chi” but I will include this statement for the local County Engineer, maybe he is?
“US Department of Agriculture - Forest Service EM-7170-14 or FHWA-FLP-94-006 1-202-205-0820. Once this organization went defunct a large rockery builder took it over based out of the Seattle are and a few years ago was still passing out this manual 1-425-481-3456.”
Does anyone have the EM-7170-14 or FHWA-FLP-94-006 1-202-205-0820?
I have to sleep now.
![[cheers]](/data/assets/smilies/cheers.gif "[cheers] [cheers]")
