Questions tagged [civil-engineering]
Questions that fall into the problem domain of civil engineering or one of its sub-disciplines. Questions about buildings or other structures could usually use the "structural-engineering" tag also.
136
questions with no upvoted or accepted answers
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Is there a method to determine the runoff for arid areas in developing countries?
Note: this question was totally rephrased and expanded on, addressing the comments and questions posed to the first version.
The de-facto standard source for runoff calculations in South Africa is ...
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2
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Industry standard factor of safety for ballast design
What design standards exist for the design of ballast against uplift forces, and what factor of safety against uplift do these design standards promulgate? I am familiar with a typical FS of roughly 1....
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votes
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answer
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(Non)simultaneous prestressing anchorage slip losses
Post-tensioned prestressed concrete beams suffer from a multitude of losses. When jacked, they suffer friction losses and their tension diagram is, for example (to simplify the drawing, I'm using the ...
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Conservative rebar dowel hole sizing and embedment depth
My question concerns the hole sizing and embedment depth of post installed rebar which is secured with epoxy mortar into a hole in a reinforced concrete slab.
Hole diameter sizing
My assumption #1 ...
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What is the theory behind Eurocode 1 - Part 2: Traffic loads on bridges?
I'm interested in some theory Eurocode 1: Actions on structures - Part 2: Traffic loads on bridges. How were the limits chosen (e.g. maximum deck acceleration = 3.50 m/s2)? Why is the lower limit of $...
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votes
1
answer
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Liquid splashes - who researches it, and why don't all urinal mats look the same?
I normally wear shorts in the summer, at which point I become very aware of the problem every man knows about - splashback of pee from urinals. No matter how you stand or aim, the inherent splashing ...
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Bedload discharge for canals of triangular cross-section
All the methods I know of for calculating bedload discharge are for canals of rectangular cross-section (constant depth of flow). The bedload is first computed for a unit of width (using the constant ...
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5
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Effect on pavement by light tracked vehicles with rubber inserts
Is there data available to quantify the effect on pavement by light tracked vehicles with rubber inserts. One example of such a vehicle is the M113 armored personnel carriers shown below.
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Maximum Slope of Truck Parking Lot
What is the maximum grade/gradient allowed for non-temporary (overnight or longer) parking/vehicle storage areas in parking lots for heavy-duty vehicles such as semi-trucks and buses?
All I could find ...
4
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0
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Simplifying head loss across a piping network
I am tasked with designing a compressed air piping network,with and would like to determine the pressure loss across the different layers of instruments
-now here is the 3D layout of the network. ...
- 161
4
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1
answer
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Finding the velocity of water flowing through a gravel filled pipe
I have a scenario where I have water flowing through a gravel filled pipe, and I need to find the velocity. The pipe is gravity fed (no pumps). My approach is to find the seepage velocity ($V_s$) ...
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4
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1
answer
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Is there a name for a structure/building technique comprising three arches that share a central column? (Answer Found - Triple Arch System)
I saw a few minutes of a documentary that mentioned the domed roof of the largest mosque in Istanbul is supported by the strength of sets of three arches assembled so they share a common pillar. I'd ...
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2
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Once stopped, is it possible to achieve full cement hydration?
Several sources state that if hydration is stopped during cement curing, is not possible to resume it, and final strength will be compromised. But so far, I haven't found a reliable explanation.
I ...
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0
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Any Idea of This China's "Transparent Concrete"?
I am currently make an attempt to make miniaturized version of this China's solar highway on my garage
https://www.youtube.com/watch?v=zK8FvzI3yDA
Just so i can re-evaluate the performance
However, I ...
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water leak through subterranean cable penetrations in concrete
See the image below for the detail of 4 no. cable ducts that run from a trench in a raft foundation (on the left) through an approximately 1 m square penetration in the raft foundation, through soil (...
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0
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463
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Why do we use the strain-controlled test for the compressive strength of concrete?
As you all now, a typical stress-strain curve for concrete under compression can be seen in any reinforced concrete design textbook. The decreasing part of the curve (post-peak) can be obtained by ...
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What is the kinetic energy required to impact the surface of asphalt roads?
I am trying to find estimates of the minimum kinetic energy required to impact the surface of asphalt roads as a first-order impact assessment of road functionality to rockfall (i.e. boulders hitting ...
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3
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0
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Is a Geodesic Dome (fuller dome) that floats possible? What material or engineering effort would it take?
Buckminster Fuller has popularized Geodesic Domes (invented by Dr. Walther Bauersfeld who based it on the use of convex polyhedrons), and thus, making buildings with a very large roofs that don't ...
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3
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0
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41
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What is the effect of ageing on preconsolidation pressure?
Preconsolidation pressure is the maximum effective vertical overburden stress that a particular soil sample has sustained in the past.
How far in the past does the soil remember its loading/the ...
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54
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What does it mean to do a "hot casting" of a brick?
I was talking to someone about brickmaking and he said doing a "hot casting" of a brick requires more energy and there are alternatives that use less energy. What does that mean?
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The use of Theis equation based on time
The storage coefficient (s) for artesian basin can be determined by the following equation (Theis equation):
$$s=\frac{Q}{4\pi T}\int_{\frac{r^2S}{4Tt}}^\infty\frac{e^{-u}}{u}du$$
Does this ...
3
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0
answers
317
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Heat equation for solar radiation on a wall
I'm trying to model the effects of solar radiation on a (thick) concrete wall. My assumptions are followings:
The wall behaves as an half continuum with parameters $k = 0.8 W/Km$, $\rho=2500 kg/m^3$, ...
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How to integrate ∫vᵢ(uᵢ² + vᵢ²)dA in calculating monosymmetry index of an angle?
I saw this question asking about calculating monosymmetry index of an unequal angle. What I need is a formula to calculate $\int v_i{(u_i}^2 + {v_i}^2)\text{d}A$, given the depth $d$, breadth $b$ and ...
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How to obtain relative movement and rotation of bridge bearings?
In structural analysis of a bridge using whatever software, such as MIDAS or SAP 2000, it is easy to obtain the deformation of individual nodes. However, for bearings, what we want is the relative ...
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3
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0
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71
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How is a merge left or a merge right chosen?
Recently a certain 2 lane exit ramp changed from merge right to merge left, but the entrance ramp immediately preceding it is merge right. Why was this changed? In a given circumstance, what dictates ...
3
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0
answers
855
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What are the moisture related issues in the use of Stucco and EIFS in the building construction Industry?
I am investigating the use of stucco masonry versus Exterior Insulation and Finish Systems (EIFS) in the construction industry. I have no knowledge or training in this matter and my knowledge is ...
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3
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0
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Engineering in Kazakhstan and Rainfall Intensity
We are about to commence a large project in Astana, Kazakhstan worth several hundred million dollars. The design of Stormwater quantity, quality, and hydrology will be a large component of our works, ...
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2
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0
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47
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Thermal Expansion and Stress in a Heated Beam
Consider the case of a beam that is supported in such a way that expansion can occur freely. Suppose that the beam is heated in such a way that the temperature varies with the depth of the beam. Let $...
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57
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Hencky nets/slip-line fields on the the interior of a closed domain
This is a crossed post.
The equations for Hencky nets are usually solved in the exterior of some domain; typical examples are the upper half plane or the exterior of a circle. I would like to know ...
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answers
56
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Help calculating discharge rate from a reservoir as the water level drops?
I could do with some help calculating the discharge rate from a reservoir and factoring in how that flow will decrease as the head of water decreases.
The information I have is:
Maximum height of ...
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2
votes
2
answers
189
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How to design an enclosure around the load cell (Beam type)?
Hardware and Electronics Used: Arduino UNO, HX711 ADC Load cell amplifier, Load Cell (2Kg);
Currently, I am working on a project which requires me to put load cell along with the other circuitry in an ...
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2
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0
answers
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Help sizing of lug attachment flange/plate?
Apologies for the crude drawing attached, but here goes. Given Fx, Fy, and Fz loads applied at the lug hole, I've distributed the loading into each of the 6 fasteners to size them. I've also sized the ...
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What does "Percent Trucks in Design Lane" input represent?
In the AASHTO Pavement ME program version 2.6, for the traffic input "Percent Trucks in Design Lane" is the default value of 95% based on the maximum percent of trucks that can occur in the ...
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What is this 'timber insert' on the construction drawing of a concrete parapet wall?
A sectional elevation of a concrete roof is shown below (drawing is from the early 70s):
The roof slab is dimensioned as 6" thick with what appears to be 12" parapet wall with a 'Timber ...
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What are the hypersonic Normal shock relationships?
I am learning about hypersonic flow now and there seems to be a lot of discussion about the oblique shock relationships as the Mach tends to be very large.
I was wondering what happens to the normal ...
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answers
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FEA using abaqus, and it does not follow the trend
I am doing finite element analysis of a donut shape for my school work.
I'm increasing the thickness of the object with a 1 mm increment and run FEA each time, and then comparing the maximum ...
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2
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0
answers
40
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Wearing course for Helipad
I am tasked with the design of a helipad for a remote government facility. Annex 14 Part II (ICAO Convention on International Civil Aviation) does not clearly state what materials are acceptable.
The ...
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0
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What does C20019 IN PAIRS AT 900 MAX CTS WITH 2 ROWS OF BRIDGING AT 1/3 POINTS mean in a technical drawing?
Specifically, does in pairs mean that there are 2 C20019 members per indicated line on a technical drawing?
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Difference between direction of ramming in hydraulic press?
In Printed circuit board/Plywood lamination Hydraulic Press machines (seen here).
The ramming action comes from bottom in all the machines I saw so far. For such action from bottom, excavation has to ...
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0
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How to ensure natural ventilation through a shaft?
I have a small shaft, 2.5m wide by 4m deep, sunk into the ground. Due to explosion protection I should ensure "natural ventilation" - this is the termgiven in the relevant ordinance, no air flow ...
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How to define the Clothoid Constant in Clothodial Arc ( Spiral Curve)?
Referring to the document here on IfcClothoidalArcSegment2D, we have ClothoidConstant, which is defined as
The constant $A$ (not $A^2$), that determines the ...
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answer
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Inverse analysis of one Storey structure
The displacement history of one story structure is known due to an unknown ground motion. The dynamic properties, such as mass and lateral stiffness, are known, and dimensions were also given. How to ...
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vote
3
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440
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how to determine the direction of support reactions in a truss?
Hi, I am not sure how to determine the direction of support reactions at point A and K. I know point A has a pin support, therefore, it can take in horizontal and vertical loads and point K has a ...
user38335
1
vote
3
answers
142
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TMT Steel in layers
The Site Engineer and I were arguing about the placement of the reinforcement bars in layers. The Steel technician (TMT) placed the third layer of reinforcement in the 2nd layer. I said it didn't ...
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vote
2
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Is there a specific way to simulate porous structures?
I tried to simulate an axial compression test for a lattice (porous) structure but It takes too much time and it doesn't give me the right answer (when I compare with experimental results). So, I was ...
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0
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Do we allow mass and moment of the footing itself, when calculating ground support and eccentricity of a footing?
Suppose we are designing a footing for the wall of a building. There are two checks that are crucial.
Ground support: suppose the ground is assessed as being suitable to load up to 80 kN/m2. Then a ...
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1
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0
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327
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Calculating discharge from a reservoir as the head of water decreases
Due to the dry weather we've been experiencing in the UK I need to calculate the discharge rate from some reservoirs for work and how the dropping water level will result in a reduced head and so a ...
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1
answer
144
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How to professionally mount an air duct through a core hole in limestone brickwork
We need to add ventilation holes to an existing building. The holes will be core-hole drilled through a limestone brick wall. The bricks have crevices. The contractor is acting stupid and obstructive ...
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vote
0
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How much seawater could be desalinated using the waste heat from a powerplant?
I've done some rough calculations on how much water could be produced by using the waste heat of a powerplant to boil seawater.
I'm interested in a ballpark figure and would like to know if I have a ...
- 307
1
vote
0
answers
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Heat storage mass vs. AIR in an ICF house
If we would want to build a family house (ICF) regarding operational costs, should we leave the insulation on the inside, or should we remove it from the inside?
If we would remove it, the walls ...
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