In AASHTO 8th Edition, Equation 5.6.4.6-1:
rho=(4Asp)/(dc*s) >/= 0.45(Ag/Ac-1)(f'c/fyh)
does anyone know for certain if the term "Asp" is meant to be just the area of a single bar of the size being used for the spiral, or is it twice that (i.e. "2 legs" as for shear reinforcing)? I have a 42"...
A friend's house has a garage with a concrete slab "roof" that is the floor of the living space above. House built probably in the 1920s. Most of the concrete cover has spalled off the slab soffit in lines following the rebar (orthogonal grid)and the rebar is obviously corroded. I haven't been...
Question about the following provision of the AASHTO LRFD Bridge Design Specifications:
Section 5.9.4.2.2 - Tension Stresses
Table 5.9.4.2.2.-1 - Tensile Stress Limits in Prestressed Concrete at Service Limit State after Losses, Fully Prestressed Components
Other Than Segmentally Constructed...
Question about the following provision of the AASHTO LRFD Bridge Design Specifications:
Section 5.9.4.2.2 - Tension Stresses
Table 5.9.4.2.2.-1 - Tensile Stress Limits in Prestressed Concrete at Service Limit State after Losses, Fully Prestressed Components
Other Than Segmentally Constructed...
Section 10.6.3.4 of the AASHTO LRFD Bridge Design Specifications gives provisions for calculating sliding resistance of spread footings. For footings on clay, the specifications state that the sliding resistance shall equal the cohesion of the clay. This is my first use of this particular...
Section 10.6.3.4 of the AASHTO LRFD Bridge Design Specifications gives provisions for calculating sliding resistance of spread footings. For footings on clay, the specifications state that the sliding resistance shall equal the cohesion of the clay. This is my first use of this particular...
Section 10.6.3.4 of the AASHTO LRFD Bridge Design Specifications gives provisions for calculating sliding resistance of spread footings. For footings on clay, the specifications state that the sliding resistance shall equal the cohesion of the clay. This is my first use of this particular...
Designing a steel beam vehicular bridge with a composite concrete deck. Initial run resulted in a W21x68 as the optimal section. However, shear stud design would require rows of (3) 7/8" diameter studs spaced transversely across the beam flange in some locations. The problem is that the flange...
I posed this question over in the Structural Engineering forum, but it occurred to me that perhaps the retaining wall guys might have had some first hand experience with this. In short we have a contractor proposing to utilize salvaged steel railroad rail as reinforcement for drilled concrete...
I have been tasked with the review of a soldier pile type wall design wherein the design-build contractor is proposing to use steel railroad rails placed into a drilled hole and filled with structural concrete. I am trying to determine if this can be treated as a composite beam based on the...
What are the reasons for using a strut and tie model for deep beams? Will traditional design methods for flexure (Whitney stress block) and shear yield unconservative results for deep beams? Or does the strut and tie model just produce more economical designs?
I have never used strut and tie...
We are designing a steel sheet pile retaining wall that will be used as temporary shoring for construction of a bridge foundation, during which it will retain about a 6 ft. depth of cut. It will be left in place after construction is complete and will then serve as a permanent retaining wall to...
Does anyone know what the lateral earth pressure would be for the case of a narrow (~2 feet) zone of granular backfill placed between two parallel walls?
The specific case is the basement wall of a condo we were asked to investigate. The masonry block basement wall is buckling inward and we are...
Does anyone have any experience with /recommendations for excavating for utility trenches in the vicintiy of soil nails? Within what distance from the nails should excavation be resticted or prohibited?
