http://www.preethamgranites.com/cracks-building-foundation-settlement/Providing structural solutions for differential settlement is a challenge that face by many structural Engineers during their career.Generally ,allowable differential settlement is 20mm ,maximum, between two adjacent columns. This is based on the 75% of the maximum allowable cumulative settlement for shallow foundations of 25mm. Below are few general solutions that widely used to cope the differential settlement problems;11.)Provision of
In the last post, I assured that I will write on the measures which we took, conforming the enhance protection of the bridges and embankments against damages caused by scour. After a devastating rainy season which happened during the project implementation, we were convinced on the additional requirements of the protection measures which were not included in the original designs. ...
Question ( Reader from Contractor Blog)Questionif i get a core sample of concrete in a newly built existing structure and found out based on laboratory test that the compresive strength of the sample is below 3000psi, does it conclude that the structure is unsafe or structurally unsound.Are there other factors needed to be considered in determining structural soundness of the ...
Question : Many engineers in SL simply neglect the skin friction ( not negative SF) of the end bearing piles. Obviously it leads to lager diameter and greater cost but safe design..Generally, here, the cast in situ piles are considered as end bearing piles and are normally socketed in to bed rock.However recently I saw a pile design which I ...
In bored pile construction , there are few widely spread methods in stabilizing the bored hole. This post discusses these methods in summary.The most common and economical solution is to use bentonite and the main idea behind using bentonite is to stabilize the bored hole. Owing to the high density, it prevents water inflow to the hole. However, if it ...
In structural engineering, the Flat Slab is identified as a slab which is supported generally without beams by columns with or without column heads. However, I have understood that Flat Slab designs are not quite popular in Sri Lanka, may be owing to its complexity in design, detail and construction. But things what I am going to discuss here are ...
As a Structural Bridge Engineer, analyzing, design and review of prestress girders is part of my everyday assignments. To make my life easy, I have made my own spreadsheets as well as finite element tools to complete above tasks. Design or review, my approach is two way. 1. Spreadsheet 2. Finite Element Model - either using commercially available software Midas Civil, Bridge ...
I came across this problem last year. Although the issue has been solved, still I think we can share our views on this.The problem occurred on 19m long pre tensioned PSC beam. The cracks, in the range of 0.2 mm – 0.5 mm, were noticed on the top flanges of the 19 m beams and near the two lifting positions ...
Sometime back, I came across a problem to provide a shoring solution for an excavation.The Client requested a cost effective solution to retain 7 m of earth in a deep excavation. I provided below mentioned two options with cost comparison. 1. Driving of steel sheet pile2. Soldier piles. Option -1 was economical and technical feasible as owing to existence of ...
Many times, during my site inspections, I have found fault with the Contractors for providing an inadequate cover for the reinforcements in R.C structures. Obviously inadequate cover for the R.F has to be rectified immediately as less cover causes the larger crack widths in concrete and thereby it exposes the reinforcement to surrounding environment to get corroded. This is ...
This time I thought to write something reference to the foundation design in bridges. Typically two types of foundations can see in Sri Lanka. i.e1. Spread Footing2. Pile FoundationI thought to discuss why pile design is defer in Bridges compar
I thought to start my first blog with a simple but very useful information to civil engineers and technical officers.I have seen very senior engineers going through their handbooks when they were been asked to calculate the weight of a particular length of a R/F bars. But if you can memorize a simple data, it is totally unnecessary to refer ...
