I'm trying to figure a way to install piers between a reinforced concrete grade beam above, and competent rock below. Reinforcing for the pier will be a single number 9 bar, doweled into the existing grade beam. After the bar is in place, I will have to put the sonotube around it, and the only...
I've put a great deal of time and thought into an innovative retaining wall design, and am about to implement this design for the first time on my own property. This design is my baby, unique as far as I can discern (and I've really looked) and my objective is to employ it repeatedly as a...
I'm working on an innovative basement design for existing homes, with an emphasis on speed and economy of construction, in addition to long-term performance. The basement floor will bear on competent grey limestone, and will support interior columns, but will not support the perimeter walls...
I'm just a dumb civil/structural, so please forgive my ignorance. A residential split AC system is clearly intended to operate over a wide range of ambient outdoor temps. Here in Dallas, we can expect a system to run from 78 degrees to 112 degrees F. I know that excessive subcooling or...
I'm in structures, so bear with me.
We often deal in wind pressures on vertical surfaces, and obviously have to design systems to resist them. I am looking at a small job: an 18' high wall, over 100' long, with the bottom close to or on the ground. It is a temporary plywood wall meant to...
I am installing solar panels on my home, and trying to make it a bit more economically feasible, I have bought all used panels. These panels are in a variety of power ratings: 50, 64, 75, 100, and 180 watts, but the peak voltage ratings are similar, all in the 16-17 volt range. This will be a...
I've got a structural situation that seems apparently more than adequate from an intuitive standpoint, and certainly looks plenty strong to the untrained eye, but is pretty damned difficult to rationally model:
A rectangular catch basin with 6" thick walls is site cast around a 24" RCP with 3"...
In AASHTO section 10.38.5.1, the value "S(sub)u," the ultimate strength of a shear connector, is given as a function of the stud diameter, f'c, and E of the concrete. Assuming 60ksi shear strength for the studs, and 150 pcf concrete, with 4000 psi concrete and above, the AASHTO calculation of...
What is the best way to approach asymmetric bending forces in wood? For instance, if you have a pitched-roof purlin with the narrow face against the sheathing, such that dimension "d" is not vertical, how do you calculate Fbmax for snow load?
Would you break the vertical load into components...
Can anyone recommend a book on timber framing/post and beam construction written for engineers, or with a depth of detail that would be useful for an engineer? I'm afraid to go looking on Amazon because most books there are written for prospective home buyers and timber framers, and I doubt too...
I have a situation wherein a garage slab is to meet natural grade at the entrance, but is well above grade at the other end. The area under the slab will be a wedge shaped dead space, with a full wall at the end, and tapering walls on the sides. I am looking at three options: 1) span deck...
Because it looks like a simple, inexpensive retaining wall, I get a lot of requests from homeowners and some builders to design eco-block retaining walls. Many of them, especially the homeowners, incorrectly believe that eco-blocks can effectively form tall gravity walls, even to ridiculous...
When designing shear walls, I have typically used only the dead weight of the wall itself (studs & sheathing) to calc the required holddowns. Of course, the wall could never lift independently of the rest of the bldg. What is a more realistic approach to obtaining the actual deadweight that...
For the wall mentioned in previous post:
What is or where could I find a safe value for c (rock mass cohesion intercept) for moderately to highly fractured basalt? I want to use the rock dowels to help in resisting overturning, but I want to be very conservative in estimating the tensile...
I am designing a wall retaining a 1.5:1 back slope. The wall will be more than 9' high above finish grade (acp) and will probably be 11' high total, with the base resting on basalt. To prevent sliding, I was wanting to dowel into the rock with the #6 bars that are also the tension steel for the...
