7
votes
Accepted
Why are home geothermal systems usable anywhere in the U.S. but industrial geothermal plants limited in geographical use?
Because they're two completely different systems that have, in some circles, accidentally been given the same names.
The things that are sometimes (particularly in the USA) called home geothermal ...
- 3,771
6
votes
Difference between 'plastic yielding' , 'plastic yield strength', plastic strength' and 'plastic stress'?
All these terms refer to the effect of loading on the deformation of materials. Let us assume that we start with zero load and zero deformation.
Elastic deformation
If you increase the load you ...
- 1,453
5
votes
Accepted
What is the difference between "Crushed Stone" and "Crushed Gravel" aggregate?
It's of importance to note that historically, "stone", "gravel", and many other related terms have great regional variability. It is always advised to make certain what is meant by such terms when ...
- 1,176
4
votes
Accepted
Why is this construction site pouring gravel over a wire mesh, and then covering it with dirt?
You are correct, this is the subbase that the foundations will be built on top of.
The gravel can be used as you say for water run off but it also allows for a level base on which to lay the ...
- 170
4
votes
Accepted
Are pumps used in geothermal systems
They are both correct. There are actually a number of different types of geothermal power plant with the most common being, dry steam, flash steam, and binary cycle.
Dry steam plants require pumps ...
- 170
3
votes
How do you convert "kps" to Pounds per Square Foot (psf)?
I've done some searching, according to this converter kps or KPS stands for Kilo Pascal, but don't use that abbreviation.
The actual abbreviation for Pascal is Pa, and for kilo a small k, combined kPa....
- 1,186
3
votes
Accepted
To Which distance Punching Shear Reinforcement is placed in Mat Foundation?
For a more complete discussion see: ACI 421.1R-08 - Guide to Shear Reinforcement for Slabs.
But in principle you need to continue to provide punching shear reinforcement until the shear capacity of ...
- 2,651
3
votes
Is there a torsion test in rocks?
I am unaware of a torsion test for rock. Shear, compression & tensile strength tests yes, but not torsion.
All the civil engineers, mining engineers and geotechnical engineers I have worked with ...
- 9,752
3
votes
The best foundation type?
It is the right foundation type that is the best. Not necessarily pylons or any one size fits all solution.
Design of foundation is a process tightly tied to the type of soil, geology of the site, ...
- 22.8k
3
votes
Accepted
What is the meaning of these two inverted triangle water table symbols in a borehole record?
The water table in some locations may vary during the day or over time. For this reason, the borehole drilling process includes waiting periods to see if there are any changes to the water table.
The ...
- 13.1k
3
votes
how much force is required to drive a fence post 2ft into soil or sand using a hydraulic press?
What you are proposing is similar to the cone penetration test (CPT) used by geotechnical engineers to characterize the soil layers of a site before construction.
The measured resistance to a ...
- 154
3
votes
Accepted
what kind of expert can analyze drought effect on rock fall risk?
You need to consult a geomechanical engineer. Sometimes they can also be referred to as geotechnical engineers.
A geologist can tell you overall geology of the region of interest, but to determine ...
- 9,752
2
votes
Active vs passive earth pressure
If a retaining wall is immobile, it incurs lateral soil pressure from both sides, and that is the so called resting pressure.
When the retaining wall, due to load from the retained soil massive, ...
2
votes
Accepted
Base or foundation?
The part of the building that is in contact with the soil is the foundation:
the lowest division of a building, wall, or the like, usually of masonry and partly or wholly below the surface of ...
- 3,133
2
votes
Why dig out and then fill in before building a large structure?
In addition to the other answers, some soils (e.g. clay) expand and contract as their moisture content changes, and wet soil expands as it freezes. This movement is rarely even across site, and ...
- 171
2
votes
Accepted
Postion of overturning moment for retaining wall
I have designed plenty of (probably several dozen) retaining walls with long toes in situations with low allowable bearing capacities. Usually designed with RetainPro (which is not FEA), but also ...
- 1,176
2
votes
Base or foundation?
As was said in the other answers, the part in contact with the soil is the "foundation", or perhaps "footing" (a specific type of foundation, but there are also piles, drilled shafts, rafts - all of ...
- 1,176
2
votes
Load conversion for geotech problem
In the comments you seem to already understand that kN/m/m means "kN per meter along your screen, per meter into your screen". This can be simplified as kN/m2: kN per meter in each direction.
The ...
- 13.1k
2
votes
What is a safe soil load to avoid settlement?
The PRESUMPTIVE LOAD-BEARING VALUES table in the IBC is meant to be used with ASD loads (see section 1806.1). As such there are already factors of safety "built in" to those values. The only thing I ...
- 1,176
2
votes
Bored Pile construction Procedures When having Water in the ground
Water accumulating in the bottom of the bore is not a concern, as long as concrete is delivered at the bottom of the bore via a hose.
Concrete with the slump of less than 4inches with some ...
- 22.8k
2
votes
At what level is the Grade Beam most effective at pile cap level or at Slab-on-grade level?
The grade beam typically must be supported by competent soil. In some cases they are designed as per recommendation of soils report for specific tasks such as integrating soldier piles or supporting ...
- 22.8k
2
votes
Drained and undrained shear strength of clay correlated?
They are certainly correlated but there is no simple relationship. A commonly used rule of thumb, where I live, is $c'=0.1c_u$ for overconsolidated clays and zero otherwise, but reality is much more ...
- 1,288
2
votes
Accepted
Missing items in geotechnical reports
A structural engineer should never conduct their own soil testing unless being supervised by a competent person. This is not your area of expertise, let the geotechnical engineer do their job.
...
- 266
2
votes
Low pile capacity during pile driving
Since you said that the piles are not reaching the desired capacity, I am assuming that these are friction piles instead of bearing piles.
There are two ways in which the capacity of friction piles ...
- 10.7k
2
votes
how much force is required to drive a fence post 2ft into soil or sand using a hydraulic press?
This is a highly technical topic, that is very difficult to explain in this space. In general, we can't get accurate/meaningful soil resistances (bearing, friction) until actually driving the pile/...
- 8,232
2
votes
Soil movement due to open cut excavation
The program is not capable of discretizing the line load as the real soil medium, thus for a long uniform load, it mobilized/engaged more soil below as opposed to the finite soil mass under the ...
- 8,232
2
votes
What is this geotechnical mechanical drop device and what does it measure?
This looks like Light weight deflectometer used to determine the deflection capacity of the subgrade under the dynamic load. It is suitable for monitoring and testing the
construction quality of ...
- 24.3k
2
votes
Would it be possible to generate electricity from continental drift?
If not lending ourselves to overly unrealistic scenarios, then no. In theory however, then yes.
According to National Geographic, "The North American and Eurasian tectonic plates, for example, ...
- 369
2
votes
Accepted
Brainstorming - Is it practically possible to modify Air Earth Tunnel and Geothermal Heating & Cooling Sytem
A technique used for many years.
Search for "puit canadienne" - at least that was where I started when I was designing the one we put in in Switzerland.
put 30m of pipe (3 tubes 25cm ...
- 16k
1
vote
Modelling Soil in a Scale Model
Modeling soil behavior in a scaled-down lab system requires that the force of gravity be scaled up to maintain dynamic similitude. This requires the scaled system to be spun in a centrifuge at a speed ...
- 15.3k
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