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.

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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 ...
SlydeRule's user avatar
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7 votes
2 answers
637 views

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....
Rick's user avatar
  • 1,166
7 votes
1 answer
777 views

(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 ...
Wasabi's user avatar
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6 votes
0 answers
4k views

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 ...
egg's user avatar
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6 votes
0 answers
135 views

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 $...
megamicke's user avatar
5 votes
1 answer
141 views

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 ...
Graham's user avatar
  • 639
5 votes
0 answers
46 views

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 ...
J. I.'s user avatar
  • 51
5 votes
0 answers
103 views

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.
David's user avatar
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4 votes
0 answers
141 views

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 ...
CoastCity Lapse 00crashtest's user avatar
4 votes
0 answers
134 views

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. ...
udidosa's user avatar
  • 161
4 votes
1 answer
812 views

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 ($V_s$) ...
S User's user avatar
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4 votes
1 answer
107 views

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 ...
Toph117's user avatar
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3 votes
2 answers
302 views

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 ...
angelpeream's user avatar
3 votes
0 answers
71 views

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 ...
talkingpandas's user avatar
3 votes
0 answers
73 views

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 (...
egg's user avatar
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3 votes
0 answers
511 views

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 ...
alpos2801's user avatar
3 votes
0 answers
49 views

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 ...
e5k's user avatar
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3 votes
3 answers
167 views

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 ...
Hecate Newb's user avatar
3 votes
0 answers
42 views

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 ...
Bibek Panthi's user avatar
3 votes
0 answers
55 views

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?
opaque_dragon's user avatar
3 votes
0 answers
38 views

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 ...
Gevor Hakobyan's user avatar
3 votes
0 answers
327 views

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 $k = 0.8 W/Km$, $\rho=2500 kg/m^3$, ...
David's user avatar
  • 131
3 votes
0 answers
270 views

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 ...
Jennifer's user avatar
  • 271
3 votes
0 answers
208 views

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 ...
Wilkie's user avatar
  • 31
3 votes
0 answers
71 views

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 ...
TrottingGoatParade's user avatar
3 votes
0 answers
866 views

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 ...
Mahendra Gunawardena's user avatar
3 votes
0 answers
178 views

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, ...
Louis Russell's user avatar
2 votes
0 answers
76 views

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 $...
CrystalTerry's user avatar
2 votes
0 answers
57 views

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 ...
Daniel Castro's user avatar
2 votes
0 answers
67 views

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 ...
Sean's user avatar
  • 21
2 votes
2 answers
205 views

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 ...
Ganesh Hosur's user avatar
2 votes
0 answers
49 views

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 ...
Hunter's user avatar
  • 79
2 votes
0 answers
97 views

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 ...
Nicolet's user avatar
  • 21
2 votes
0 answers
49 views

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 ...
egg's user avatar
  • 857
2 votes
0 answers
35 views

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 ...
user1234's user avatar
2 votes
0 answers
94 views

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 ...
Kwun's user avatar
  • 21
2 votes
0 answers
40 views

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 ...
SlydeRule's user avatar
  • 1,226
2 votes
0 answers
134 views

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?
Berry's user avatar
  • 21
2 votes
0 answers
55 views

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 ...
Hanu's user avatar
  • 31
2 votes
0 answers
28 views

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 ...
mart's user avatar
  • 4,781
2 votes
0 answers
166 views

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 ...
Graviton's user avatar
  • 1,264
1 vote
1 answer
37 views

Pumping water from under concrete slab basement

I have this situation, and wanted someone's opinion. Info: Concrete foundation basement, slab floor Weeping tiles and a sump pump is present / operational The house is near a pond. Grading is alright,...
CrazyFox01's user avatar
1 vote
1 answer
35 views

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 ...
Dr.Anime's user avatar
1 vote
3 answers
916 views

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 ...
user avatar
1 vote
3 answers
200 views

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 ...
Jatin Sharma's user avatar
1 vote
2 answers
64 views

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 ...
Goli's user avatar
  • 11
1 vote
0 answers
17 views

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 ...
Stilez's user avatar
  • 571
1 vote
0 answers
485 views

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 ...
Sean's user avatar
  • 11
1 vote
1 answer
156 views

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 ...
mart's user avatar
  • 4,781
1 vote
0 answers
34 views

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 ...
Brinn Belyea's user avatar