Underwater Construction Challenges
Many laborers are fighting hard against the violent ocean currents to complete the construction of an underwater Bridge Pier are you able to spot a mistake made by the chief construction engineer here this mistake Will result in a catastrophe welcome to civil engineering’s most challenging task underwater construction even though we call it underwater construction today’s Engineers avoid water all together when building an underwater structure to remove water from your construction area you must first build a temporary Dam called a coffer Dam working directly under the water is far from a practical method the next question that arises is how to build the Coffer Dam under the water the first step is to erect these guide piles with the help of a pile driving Hammer machine the guide piles provide guidance for the construction of the Coffer Dam then workers will drive many sheet piles in the soil with the help of the same machine these sheet piles have interlocking connections at both ends of the section such a clever interlocking mechanism means that water leakage will be minimal the sheet piles are driven under the ocean bed till they reach the Bedrock the order of piling is from the corner to the center the alignment can be maintained this way have you noticed anything special about the pile driving Hammer machine it isn’t just pushing the sheet piles down you can imagine easily what would happen if the sheet piles were pushed into the soil to penetrate the soil the machine uses vibration If You observe carefully you’ll see these tiny but fast vibrations the specialty of this machine lies in the fact that it consists of two counter rotating eccentric weights the purpose of these weights is to induce vibration in a machine this flat surface looking ship called a barge is employed to carry machinery and components that are required on the construction site now we’re ready for the big phase of the construction project pumping out the water from the Coffer Dam however before doing all this work the engineers had a major assignment to do let’s see what this was
Preparing the Foundation: Soil Testing and Pile Driving
before getting into the water pumping phase the engineers of the project had to do a detailed geotechnical study of the soil on which the Coffer dam was going to be constructed they selected the land so that it would be able to carry the load of the permanent structure the most commonly used test for measuring soil strength is an insitu test called a cone penetration test you can see how the cone penetration test device is kept on the ocean bed the conical tip of the device penetrates in the soil and sensors send back friction and soil resistance values they they will continue the penetration till the point they reach the Bedrock you can see the sudden jump in the resistance value once the Bedrock is reached with the help of this handy test the engineers know how deep the sheet piles must be driven the sheet piles should reach the Bedrock now let’s jump back to the project and begin pumping water out as the water level lowers you’ll notice water leakage between the sheet piles this is due to differential pressure of the water single layer sheet piles are failing so we need to double them the space between these walls of sheet piles is generally filled with granular material such as sand gravel or broken rock this double layered Coffer Dam will effectively resist water leakage Between the Sheets now let’s remove all the water from the Coffer Dam luckily there’s no visible water leakage what happened the entire Coffer Dam collapsed inward earlier when the water was present on both sides the force acting on the Coffer Dam due to the water pressure was being canceled out you can easily understand the reason for this however when the water from this volume disappears there will be a huge inward Force which destroys the Coffer Dam the inward collapse of sheet piles can be prevented by erecting a bracing frame structure by the side of the sheet piles the bracing frame system comprises components like whales struts and braces the connection between these whales and struts is bolted as Illustrated here these horizontal members called struts provide lateral support which can resist inward movement to the Coffer Dam walls the Coffer dam is super strong now and it’s reached the Bedrock let’s dry the water now can you predict what will happen now here I have made a coffer Dum a small but cute Coffer Dum isn’t it
How to Build a Strong and Leak-Proof Underwater Bridge Pier with Coffer Dams
let’s see now what happens if I remove water from the Coffer Dam I’m removing the water did you see that a beautiful U shape the water particles are traveling like a u shape below the Coffer down this is because of the water paral differential the same thing will happen inside of cofam as well when you remove water from that similar to The Experiment water seepage happens in our Coffer Dam also the technique to prevent water seepage are difficult to accomplish so let’s pump this seepage water out continuously if the soil above the hard strata is removed and concreting is done on the hard strata our underwater project is half done this is called the concrete seal course technique the concrete seal course will also act as a strong footing preventing any water leakage let’s see how this is done the removal of the soil from the Coffer dam is usually done using clamshell buckets these buckets are operated by an excavator doesn’t the operation of the clamshell Bucket look pretty cool the next stage concrete seal course to make sure the concrete seal course is bonded strongly with the Bedrock we need a few piles which penetrate into the Bedrock the vibrating Hammer machine comes to help again it pushes a few hollow steel pipes into the Bedrock the Hard Rock within this cylinder is removed with the help of an augur machine now it’s time to place reinforcement bars into the cavity and pour concrete once the piles are ready we can build the concrete seal course above since seepage water is present on this base always the seal course concreting is carried out using the try method this includes a hopper bucket and a long segmented pipe specialized cement with high workability is used to concrete the floor a thick plug is installed at the bottom of the try pipe to prevent water from getting inside the pipe after some time this pipe is lifted with a jerk causing concrete to pour down and the bottom plug to be removed during this process the discharge end of the try pipe is continuously kept submerged in the concrete so that the rete which is getting poured is less likely to mix with the surrounding seepage water now that the concrete seal course is ready it’s time to tackle the remaining construction work the water seepage is efficiently blocked by this structure
Constructing the Bridge Pier and Removing the Coffer Dam
workers lay out the skeleton of high quality reinforced bars to construct the footing shaft of the bridge Pier because the bridge Pier structure is going to remain in the water Engineers ensure that the materials to be used in the construction are of the best quality they must succeed successfully bear the water pressure as well as the load of the bridge as the skeleton of the bridge Pier keeps on progressing arrangements are made to pour concrete in the structure once concrete is completely poured into the skeleton this structure is kept undisturbed to gain strength usually a bridge Pier takes 14 to 28 days to gain complete strength once the bridge Pier gains enough strength the Coffer dam is of no use and is an eyes sore so the engineers remove it however removing the Coffer dam below the level of the concrete seal course can affect the strength of the whole structure as a result Engineers cut the sheet piles at this level here it is this strong Bridge Pier is ready to support a heavy bridge
Why Trade Contractors Must Care About Productivity Gains
Predict this productivity increase. The owners may be excited about that. The general contractor may be excited about that. But you have to be excited if you’re a trade contractor. Now, Morson does a lot of self-perform work. So when their productivity goes up in concrete formwork, they pocket a lot of money, or they turn it into a competitive advantage. And 2.95 average direct cost reduction. This does not include the indirect cost, but a 3% almost average savings. That would be 7.5 million on your 250 million dollar project.
These are 18 case studies. You can read about them, each individual project and the story behind each one and how they came up with these. But it shows to me a quite impressive sophistication. So when I say the coaching for executives, for me, is really simple: don’t create a BIM initiative. It is too easy for me to push back. “We never had BIM in the old days, and we used to make a fine profit.” Well, it is not the old days. And I am not asking you to use BIM. If you can find another way to get this performance, if you can save 17 million on 250 million, I don’t care if you use a broom.
Start by Defining the Current State and Relationship
But crafting this worthwhile initiative is what I showed you earlier on this list of defining the current state. So the relationship that I would like to have with my customers, and I encourage our partners to have locally with the local customers, is to create that fabric of the relationship that allows you to go through the calculations. Do the background as much as you can. Understand your current environment.
Maybe there’s some academic research. One of the things you can do is get your hands on a couple of these research papers and just let folks read them. Get them started. Maybe there’s a free viewer and you can pick a model off the web somewhere, and have them fly around the model. Just begin to have an understanding of what BIM is, what results are coming in around the world, and what that means to us.
When Honesty About Past Failures Sparks Real Change
This is where about 60 or 70% of my customers will really be honest with me. They’ll say, “Look, we lost our shirts on a couple of projects.” Some owners really open up to me. Some contractors really open up to me with their own case studies. When we go through the opportunities in the middle, I don’t talk about products. If you look at that list, it’s about performance indicators.
What I’m trying to do around the world is to find people out there who have the same interest as I do. I would just like to be world-class at measuring performance of project teams. I’d like to really be good at leading indicators, which predict performance. Executives will be really glad to work with me if I can help them predict whether they may have a problem in the future. That leading indicator allows for intervention to keep that performance up.
How to Achieve Productivity Gains Without Making It All About BIM
On the right, I’ve got just a list of things I think belong in the initiative as we go forward. It includes that personal touch. But I do find executives at the highest level, it is much easier for them to imagine themselves saying, “We’re going to try to improve performance and measure it,” than it is to say, “We’re going to do a BIM implementation across the company, and everybody’s going to learn how to run this stuff.” Well, a lot of folks don’t have to know how to run it. They need to know how to manage this new process.
This piece of it, what you just said, is exactly what we’ve been doing at Cons Construction. So, for the last six or seven years, we’ve been really fortunate to be very successful. We’ve been on a great uphill curve in terms of growth, revenue, and everything else. Honestly, it all started when we got honest with ourselves and decided to start measuring everything that we could. That wasn’t a BIM initiative. It was just, “Let’s measure everything we can and track what we’re doing.”
It’s something that everybody knows about. When people come in on the first day, that’s what they hear. It’s just part of our culture at this point, trying to measure everything. It’s not always easy. Sometimes it’s hard. Sometimes you have to step back and be honest with yourself again. But I don’t think it’s a coincidence that our success has been at exactly the same time we decided to really measure our performance wherever we are.
What I like about the sound of that is when you improve, you know it. And you can celebrate. Just like making your schedule milestones on a project, you make a milestone, you celebrate, then you go back to work.
Moving Beyond Technology: Performance-Driven Construction Culture
That’s very interesting. That’s a mark for me, a mark of the most sophisticated contractors. They’re not talking so much about technology. They’re talking about performance. Once they’re talking about performance, they sooner or later say, “Let’s measure this.” The word I wanted to come up with as I heard you talking is: you’re beginning to harvest intelligence from the data that you have. You’re measuring. This data has been sitting around forever, it’s in one form or another, in one file, in one server.
So you are becoming sophisticated at harvesting this big data. I think we’re at the place where I say, I don’t say thank you yet, I think we open it up for questions. I hope this has been instructive so far. What you’ve seen is a structured approach to evaluating the financial benefit of an initiative. We call it BIM in the title. But the implementation may not have that much BIM in the announcement or in its name.
It really comes down to trying to harvest every penny, in every phase, for every stakeholder, and then calculate what’s your piece, and what are you willing to invest to get good at harvesting that piece.
At the heart of what we do as engineers is not just building structures, but making those structures smarter, more responsive, and more valuable at every stage. Whether it’s constructing underwater foundations or implementing BIM-driven strategies, what truly separates the best in our field is not the tools alone, but how well we measure and act on performance. Too often, data sits untouched, scattered across servers. But when we begin to harvest that intelligence deliberately, tracking cost, value, and outcomes, we shift from just using tech to building a culture of accountability and continuous improvement. And that’s where the real ROI lives. For every initiative, for every stakeholder, and for every engineering leader asking, what’s my piece, and how can I sharpen it, this is where your competitive edge begins.