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.

90 questions with no upvoted or accepted answers
Filter by
Sorted by
Tagged with
18
votes
1answer
426 views

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 ...
6
votes
1answer
360 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....
6
votes
1answer
697 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 ...
5
votes
0answers
631 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 ...
5
votes
0answers
120 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 $...
4
votes
0answers
38 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 ...
4
votes
0answers
97 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.
3
votes
0answers
87 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. ...
3
votes
1answer
393 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 ($V_s$) ...
2
votes
2answers
77 views

How is high static water pressure avoided in municipal water systems?

Most cities get their water supply from local sources (springs, rivers, lakes) so the pressure in the system is never more than what is produced by the pumps. But some cities get their water from ...
2
votes
0answers
61 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 ...
2
votes
0answers
31 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 (...
2
votes
0answers
203 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 ...
2
votes
0answers
39 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 ...
2
votes
0answers
66 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 ...
2
votes
0answers
25 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 ...
2
votes
0answers
78 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 ...
2
votes
0answers
52 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 ...
2
votes
0answers
52 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?
2
votes
0answers
33 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 ...
2
votes
0answers
277 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 $k = 0.8 W/Km$, $\rho=2500 kg/m^3$, ...
2
votes
0answers
195 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 ...
2
votes
0answers
64 views

Is there a name for a structure/building technique comprising three arches that share a central column?

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 ...
2
votes
0answers
100 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 ...
2
votes
0answers
60 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 ...
2
votes
0answers
805 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 ...
2
votes
0answers
153 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, ...
2
votes
1answer
396 views

Is possible for a silt soil to be compacted hard as a rock?

I had been told that a silt soil, when professionally compacted (from all the laboratory essays to the compaction with a vibratory roller), ends hard as a rock, and when hit with a metal bar it makes ...
1
vote
1answer
63 views

What exactly is Hooke's law defined for?

I used to think that Hooke's law was a relationship between how much a bar under uniaxial loading deformed and the internal force (per unit area) that developed within that bar. But this clearly isn't ...
1
vote
0answers
24 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 ...
1
vote
0answers
37 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 ...
1
vote
0answers
39 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 ...
1
vote
0answers
21 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 ...
1
vote
1answer
113 views

What will be the the width of the column strip in the case of 2 different spans in the same direction?

Say we have a plan of a building as follows and it is required to be designed using DDM (Direct Design Method). since the moment needs to distributed laterally into a column and middle strips and ...
1
vote
0answers
31 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 ...
1
vote
0answers
23 views

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 ...
1
vote
0answers
38 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 ...
1
vote
0answers
87 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?
1
vote
0answers
26 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 ...
1
vote
0answers
114 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 ...
1
vote
0answers
71 views

What's the flow resistance of a honeycomb sieve?

Honeycomb sieves are starting to see applications in wastewater screening. What is the flow resistance of a honeycomb screen? I would expect something similar to the Kirschmer formula (used for bar ...
1
vote
0answers
29 views

Modeling high thermal expansion under fire

I am trying to use Ansys Workbench (Transient Thermal probably coupled with Static Structural analysis) to simulate behavior of a fire protection sleeve. It is used to seal the fire sectors in place ...
1
vote
0answers
1k views

Calculate the Euler buckling load of a column using the finite element method

I am trying to find the buckling load of following column: I started from the system of equations $P = (K + K_g(N))U$, where $K$ is the stiffness matrix of a single 2D frame element and $K_g$ is the ...
1
vote
0answers
25 views

Pavement stage construction; reduction of Structual Properties

Which properties of flexible pavement layers are reduced (discounted) in a stage construction design with an overlayed layer? Thickness of stage 1 Layers? Structural Number ? Modulus of Resilience ? ...
1
vote
0answers
39 views

Check of a nominaly pinned steel joint

I am interested how to check a nominally pined joint. Especially how to check its rotational capacity and whether i can define it as nominally pinned in structural fem model. I understand that there ...
1
vote
0answers
38 views

Is there a specific term for the car loops at an airport?

I notice that many airports allow cars to loop around the arrivals/departures. Is there a specific term for this design feature in airports?
1
vote
0answers
298 views

Shift Concrete Column by few inches

While building the foundation of a house, the concrete columns were built 15cm (6 inches) from the planned position, which is reducing the space for a door. The position that should have been there ...
1
vote
0answers
229 views

What are the general consideration for tendon profile in a post tension slab?

How the tendon profile is calculated for banded-distributed disposition? In the following figure why is the tendons profile one in the top fiber and the second in the bottom fiber? If the location is ...
1
vote
0answers
45 views

Water distribution - sizing weir buildings

I have a building to evenly split a water stream into two: Water flows into central chamber, over two weirs of equal height and length into two chambers and from there into pipelines. I'm looking for ...
1
vote
0answers
32 views

permeation properties of concrete under surface treatment

I wonder which permeation properties are critical in concrete with and without surface treatment (e.g sodium silicates-based solution) , is it air permeability,water permeability or absorption. If u ...