BIM Implementation in the Construction of a Complex Intersection of Utility Tunnels

SHENG BAO: The afternoon, everyone. I'm very happy that I have this opportunity to share with you about BIM implementation of the construction of a utility tunnel in China. BIM is really getting popular in China for recent years. And we are doing consulting for the contractor. This is their first time doing BIM and we learn along the way. First I'll show video so that you'll get a better understanding on this project. This is the video we do for the contractor.

This comprehensive--

Hmm. Something wrong with the-- hmm. I don't know. Well, it's showing on my computer, but it can not be--

AUDIENCE: [INAUDIBLE]

SHENG BAO: OK. Anyway we a--

AUDIENCE: Is it an extended desktop possibly and you can move it over. You can slide it over.

SHENG BAO: Oh, it's good? OK. OK. So this is the animation we did it for the contractor.

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- This comprehensive infrastructure enhancement project what the construction of an underground utility tunnel, an overpass, and a road in a major city in southern China. The project is 7.86 kilometers long and has five contract segments. The estimated overall cost is about 1.9 billion yuan, and the construction cost is about 1.5 billion yuan. In this project, there are four bridges that need to be demolished and rebuilt. Also, there are many existing municipal pipelines, including sewage, water supply, electricity, communication, gas, and drainage.

The project is two stages-- the existing pipeline replacement stage and the main construction stage. First, construct new sewage pipes on the north side of the road and remove the ones on the south side. Second, construct the utility tunnel and the overpass. This can be further divided into the following five steps. First, contract the utility tunnel and the substructure of the overpass. The fence is set on the south side and then the construction of the utility tunnel as well as the foundations, piers, and bearings of the overpass will be carried out.

Second, build the northern parts of the bridges. After the southern parts are open to traffic, demolish and rebuild the northern parts of the bridges. Third, construct the overpass superstructure, including the bent caps, the box gutters, as well as the road pavement. Fourth, construct the ramps of the bridges. Finally, we covered the landscape and construct the barriers separating motorized vehicles and the bicycles.

The construction of the tunnel is divided into six work zones that carry out work simultaneously. The third work zone was constructed first. The tunnel length is 204 meters, and the construction was completed on July 30, 2017. The utility tunnel contains water and a communications section, electricity section, gas section, and a rainwater section. The design of rainwater section is aimed at collecting the rainwater on the overpass, which can be used for agriculture irrigation. The water storage capacity is about 15,000 cubic meters. Most of the retaining walls of the utility tunnel are Soil Mixing Walls and the others are a combination of board piles and jet grouting piles.

The utility tunnel is cast in place with street pouring. The first step is pouring the bottom plate. The second step is pouring rainwater section. The third step is pouring the sidewalls and roots using traveling tunnel form.

Engineering challenges in the project mainly include the followings. First, this project is located in urban area with heavy traffic and many intersections, which leads to various construction scopes, tight schedule, and complicated traffic control. Second, in the sixth work zone, to avoid collisions, the utility tunnel passes downward and upward the main sewage pipelines, two bridges, and another utility tunnel. This makes the construction more challenging.

Third, the project involves the protection for the existing pipelines, especially the main sewage pipe lines close to the deep excavation or under the utility tunnel. The construction process is complicated, and the protection of the pipelines is of great importance. Finally, the project includes cofferdam construction in many locations. Before the construction of the utility tunnel, the existing bridges need to be demolished followed by the construction of the cofferdam. Their requirements for excavation deformation control is direct. And a flood prevention as well as the water and sand gushing control is of great difficulty.

In this project, BIM is mainly carried out in the following aspect. First, collaboration program. A WeChat program was developed for collaboration. The texts and images can be sorted and stored separately according to a different field issues. It can also display whether a problem is resolved or not to standardize the work process. Besides, by using a BIM platform, model navigation, markup adding, and document management can be done on the browser. Second, 3D clarification of construction techniques. With the help of 3D models, construction animations and VR technology constructability reviews were carried out to help workers understand the construction scopes in details.

Third, construction review and clash detection. During modeling, the CAD drawing were coordinated to eliminate design mistakes. Before construction, clash detection was carried out to eliminate conflicts among the tunnel, existing pipelines, and the auxiliary structures. Fourth, schedule management. Use 4D simulation to track down the missing project information and the potential conflicts in advance. Different colors were used in the model to distinguish the actual construction process from the planned one, which can help managers with schedule control.

Fifth, quantity takeoff. Link the construction schedule to this 3D model. As the project proceeds, extract quantities from the model, make cost estimates for each stage, and promptly adjust the quantity takeoff for the design modification. The construction that the utility tunnels can eliminate the overhead power lines as well as utility lines installed and maintained without disrupting the streets above. As a result, widespread efforts are undertaken to construct utility tunnels in major cities of China. It is an important way to improve the city infrastructure and upgrade the quality of urbanization.

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SHENG BAO: OK, I hope this gives you some idea of the project that we are doing. And I have the Chinese version of this video. So the contractor like to show you that every time the client come to the site. So this class is about BIM implementation to improve the construction management of our complex intersection of a utility tunnel. So I hope at the end of this class, you will have a greater understanding of BIM coordination in the construction, and also field issue tracking, and schedule management. BIM applications in the construction and so BIM implementation.

So the contents include the following. The project-- so this is comprehensive with infrastructure enhancement the project in southern China. The total length is about 7.9 kilometer. The project cost is about $1.9 billion dollars. Construction scope is about the utility tunnel, elevated highway, four bridges, rainwater collector, and auxiliary structures. So we see from this picture that the engineering challenges include numerous existing pipelines. These pipelines are below the existing roadways, and there are a couple of intersections, the roadway and utility tunnel. So the construction of these intersections are complex due to the complex traffic control and tight schedule.

And at certain locations, this utility tunnel has to go above this main sewage pipeline or under the river. So, the closest a distance between the sewage pipeline and utility tunnel is about half a meter. So the protection of the sewage pipeline is of great importance. As you can see, its very close to the bottom of the utility tunnel. And this shows the intersection of the roads. This shows the cofferdam construction at the location where the river and utility tunnel intersects.

So the goal of this project is to meet the requirements of the Construction Quality Acceptance Specification and to win the Qianjiang Cup. Its a construction cup. And also the BIM application in the construction and facility management. This is the first time for the contractor or the client to use BIM in the project. So the duration of the project is about two years. The construction of the utility tunnel is about one year.

And the first are we lay out BIM application processes with the contractor as to do the quantitative take of the scheduling, material management, and 3D clarification of construction techniques. And then we do the BIM modeling. So we use Revit combined with Civil 3D and the Dynamo to do the modeling. So we draw this alignment and the profile of the utility tunnel or the elevated highway first. And then you can see we draw the elevations. And then we export the points all of the piles, the location, and the elevation. And then delete the redundant data, and then import it in the Dynamo. We have a Dynamo program. And then we can create the contents, and the draw contents, drag the contents along the two lines. And then we can get the resulted utility tunnel or the elevated . Highway

And after we are done with the parametric modeling, we do the construction joining review. And find the contradictions between the plan and the elevation. We find out about 27 errors. And we issued construction joint review report to the contractor. At certain locations, like this one, at a certain locations, we can see that the designed pipeline is actually under the utility tunnel. So that means they have to construct the pipeline first and then construct the utility line. Usually the existing pipeline is above the utility tunnel. So, this can be more clearly seen in the 3D model as opposed to the 2D joins. There are a couple of locations and this appears.

And then after the construction joint review, we do the clash detection of the structures and pipelines. We developed a little program to draw the-- first that they have to detect that the existing pipelines under the roadway. And then we developed a little program to draw the existing pipelines according to the Excel sheet, the actual location. And then we put together the pipelines, the utility tunnel, the bearing walls, the piles of the elevated highway, and we put it there together on this model. And then we do this clash detection. We found out about 250 clashes.

And we also developed a WeChat program to track down these clashes. WeChat is widely used in China. It's about 200 million people are using which program to communicate in China, but this WeChat program, they dumping all the issue in one group of communication. You cannot sort out the communication of different issues or the photos of different issue. So we developed a program based on the WeChat to sort out the different questions and store all the data, the photo, or the text on the back stage. And then we track that issue until it solved.

And also, you can find that the clash between the support beam and the auxiliary structures, in the try out section, they have to remove this-- the support beam has to be removed before the actual auxiliary structure of construction can be carried out. That's a delay of construction time. So they move this-- so they move this supported beam away from the auxiliary structure, so that the construction can be carried out simultaneously. You can see this is in the tryout section, they are removing their supporting beam.

Collaboration platform. Like I said, the WeChat program is widely used. And its an app to installed on the phone. Because we tried out BIM Field in the iPad, but people are not that willing to use iPad in the field. And its also depend on the internet speed or something. But the WeChat, everybody uses WeChat, everybody has a cell phone, so we found that it's more convenient and practical to do this collaboration, field the issue of tracking based on this. That's why we developed this program to do field issue of tracking, schedule management, process management.

I talked a little bit about field issue tracking. I'll talk a little bit more about the schedule management later on. Schedule management. So this is what they do in the field about construction planning. They have Gantt chart to do this scheduling management, but it's not that useful. It's not that practical as this construction goes on. Well, anyway, we did this 4D simulation anyway. This is what they posted in site about the actual construction, what's completed. We developed a WeChat program to do the schedule management.

First, we talked to them and decide that what's they are going to do for the following month as the actual construction goes on, lay out what they will do for the following month, for each displaying how much concrete we'll pour, how much the reinforcement will be done. And then we collect these actual construction work in the field for each week for each discipline. And then we updated this information in the WeChat program and stored in the backstage. And then we analyzed the efficiency of each team and make predictions about the for the following work.

Also, we used a low-cost Chinese platform, BIM 365. It's a web-based browser to display the actual construction completed or delayed. Yeah, you can do the add mark or comments on this problem. 3D clarification. So we used mobile, iPad, or VR, or 3D printing to do this 3D clarification of construction techniques. We make construction animations to show that the construction of the intersection of the utility tunnel. And this is-- yeah, this video about the construction of the cofferdam and the construction of the utility tunnel. We have to build the southern part of the utility tunnel first. This is the pipeline to keep the water flowing. And then we do the northern part of the bridge.

And this is animation done by 3d Max to show the construction of the utility tunnel.

And before the field the work is carried out to we, do this meeting to show this construction review. And then we use the iPad using 360 Glue to show this detail the construction techniques on site. We also use the 3D printing to show that the structure of the intersection.

Virtual construction, like what do we watched, we have this animation to show the virtual construction. Traffic control-- so the construction of this intersection is complex, so we have five traffic control plans at the intersection. So, we use this animation to communicate with the traffic control department in the city, so that they can understand that this traffic control plan better and shorten the approval time. I have another-- yeah, this is the same. I have another video showing the construction of the utility tunnel in the intersection.

Yeah, so we have a different control plans so that it keeps the traffic going. And this shows the construction of the intersection of the utility tunnel.

We used the VR so that the client has a better view of the tunnel that they are going to construct. for quality control, we established a process that the guy doing the quality control measured the rebars behind the concrete. And then we have a checklist that what they need to take notes. And then we posted all this information by QR code, and posted on the wall. And also, we use this QR code to post to other important informations, including 2D drawings, the 3D model, and all the other important information, like material, and construction requirements, techniques.

For quantity take-off for this project, its about the concrete and steel rebars used in the utility tunnel. The steel rebar is a little different from the one used in the building. We actually have to draw all the rebars. It's a lot of work, so we do the rebars along the typical section of the utility tunnel for like 1 or 2 meters, and then we time the total length of the utility tunnel for the typical sections, and then we do the rebar joints for the exits or auxiliary structures, so it's comprised of two typical rebar sections.

Finally, about the BIM application in China. The Design Institute has tried out BIM for some years, but I don't think they do 3D collaborative design for the actual projects. Simply, they didn't have time to do these in-depth design in the front. So, what they really do is about clash detection and optimization of pipeline layout. That's what most of the design firm do. They put on some efforts, invest in training their staff in computer, buying computer and software several years ago, but their return on investment is relatively low. So right now, they're not really moving forward on the design part of the BIM.

For the contractors, it's they tried a BIM for the recent two or three years. They are very enthusiastic about the application right now. They think that the BIM will help them in the construction management, and willing to train their employees, and try out BIM application in their projects. But the lack of being specialists. And many of their contracts do BIM to increase the chance of winning the bidding or do the basic BIM functions, like quantity takeoff or quality control.

For the owners, well a lot of the bigger projects are invested by the government. And for the private ones, like the bigger real estate developer, like [? Wenke ?] or Wanda, they have tried BIM for quite some time. They are trying to develop their own BIM practice processes. For the government, although the overall return on rate of BIM in China is relatively low, but the government is really pushing forward on the technology innovation. And BIM is one of the major innovations in the AEC industry.

So the government is really pushing on this. And in the recent years, they have issued a lot of policy documents to encourage the industry to use the BIM. And although it is not mandatory in China, but I think that the-- because recently the EPCR, or engineering, procurement, construction, and modular construction in China is going really popular. I think more and more contractors will use BIM, will practice BIM. And now some of the onus or the state own their companies, they are willing to try out BIM in the facility of management, like the BIM application in hydrant. The owner also want us to try out the BIM in the facility management of utility tunnels.

So, my presentation is done. Anyone have questions can stay for the question and answer. Yeah.

AUDIENCE: I have a question. You said you managed [INAUDIBLE] or how do you manage [INAUDIBLE]

SHENG BAO: Yes, so we input all this clash issues in the app, and then we, as the construction goes on, we go to the site and make sure that the actual clashes resolved before the actual construction is carried out.

AUDIENCE: How do you are sure that when [INAUDIBLE] is it verified in some [INAUDIBLE]

SHENG BAO: Oh, well we have to put it in the app manually if it's solved or not.

AUDIENCE: Is that app still available for anyone to download, or is it just specifically made for your company?

SHENG BAO: Yes. We developed our own WeChat-based collaboration platform. We're also doing an English version, because I have some friends in the states, they also use the WeChat program to communicate to collaborate. I don't know if-- but in my group of people, they talk about the issues in the field and take photos, and yeah.

AUDIENCE: [INAUDIBLE] Do you think it's available for anyone to download or is it just for you guys?

SHENG BAO: Just for us, but later on we might want to promote it. Yeah.

AUDIENCE: Yeah, I have a question about [INAUDIBLE]

SHENG BAO: 365. You mean 365?

AUDIENCE: [INAUDIBLE]

SHENG BAO: I don't really understand your question.

AUDIENCE: For our existing utilities, [INAUDIBLE] on the ground, [INAUDIBLE]

[INTERPOSING VOICES]

SHENG BAO: They detected in the field about the location of the existing pipelines first, and then they gave you a location thing to the location and the depth of the pipelines. So we draw.

AUDIENCE: Existing utilities they were located and then stored in what software?

SHENG BAO: In Excel.

AUDIENCE: Do you use Excel? [INAUDIBLE]

SHENG BAO: Yeah, yes.

AUDIENCE: OK, so what software you use? Does it have three-dimensional [INAUDIBLE]?

SHENG BAO: We just developed a little computer program to import--

AUDIENCE: OK, which do you use? This was done in Civil 3D? You use this in [INAUDIBLE] What you use them on?

SHENG BAO: We using Civil 3D.

AUDIENCE: OK, thank you. Thank you.

SHENG BAO: Any question? All right. OK, thank you.