Determining Restraint Length for a 24-inch Ductile-Iron Water Main Encased in Concrete
Determining Restraint Length for a 24-inch Ductile-Iron Water Main Encased in Concrete
(OP)
Hi all,
I am new to the forum and I tried to use the search at the top of the page to find what I am looking for but could not come across anything useful. If I missed it please kindly direct me to the source. Also, HI!
I am currently working on a design of a 24-inch ductile-iron water main. The water main is to be no less than 5 feet below ground surface. The soils are very stiff to hard clay. Test pressure is to be 150 psi. Factor of safety is to be 1.5. I need to determine restraint lengths for various angles (22.5, 45, and 90 degrees).I have been messing around with the calculators provided by EBAA Iron and DIPRA to get a feel for the restraint length required however I am not sure if these can be applied to an concrete encased water main (per client request). I also tried a hand calculation using AWWA M41, and got in the same ballpark with my length as compared to the programs. However this is my first time really trying to do these calculations and would appreciate a reality check.
Basically can I apply equations for normally restrained joints (slip on / mechanical) to that which will be encased with concrete?
Thank you in advance for any help!
Nick
I am new to the forum and I tried to use the search at the top of the page to find what I am looking for but could not come across anything useful. If I missed it please kindly direct me to the source. Also, HI!
I am currently working on a design of a 24-inch ductile-iron water main. The water main is to be no less than 5 feet below ground surface. The soils are very stiff to hard clay. Test pressure is to be 150 psi. Factor of safety is to be 1.5. I need to determine restraint lengths for various angles (22.5, 45, and 90 degrees).I have been messing around with the calculators provided by EBAA Iron and DIPRA to get a feel for the restraint length required however I am not sure if these can be applied to an concrete encased water main (per client request). I also tried a hand calculation using AWWA M41, and got in the same ballpark with my length as compared to the programs. However this is my first time really trying to do these calculations and would appreciate a reality check.
Basically can I apply equations for normally restrained joints (slip on / mechanical) to that which will be encased with concrete?
Thank you in advance for any help!
Nick





RE: Determining Restraint Length for a 24-inch Ductile-Iron Water Main Encased in Concrete
RE: Determining Restraint Length for a 24-inch Ductile-Iron Water Main Encased in Concrete
Also, I talked with a few other engineers I work with and agree that my approach is okay because it will yield a more conservative restraint length.
RE: Determining Restraint Length for a 24-inch Ductile-Iron Water Main Encased in Concrete
RE: Determining Restraint Length for a 24-inch Ductile-Iron Water Main Encased in Concrete
Nick
RE: Determining Restraint Length for a 24-inch Ductile-Iron Water Main Encased in Concrete
RE: Determining Restraint Length for a 24-inch Ductile-Iron Water Main Encased in Concrete
RE: Determining Restraint Length for a 24-inch Ductile-Iron Water Main Encased in Concrete
I agree with everyone that there are better ways of doing this, I was more or less seeing if my theory was sound for the calculation of the lengths.
I appreciate everyone input and will consider these issues during the design and meetings.
Nick