Perform detailed bridge girder design and analysis in InfraWorks.
Transcript
00:04
Following on from our preliminary design using the line beam analysis, we are going to generate, automatically,
00:10
a complete grillage model.
00:14
Using the refined analysis option, we can configure how the grillage is to be generated.
00:21
Once the generation has been completed, we can then preview the results and load the model into Structural Bridge Design.
00:33
In this example, the first three spans were chosen for generation, and we can see that all the necessary parts are available,
00:40
including the alignment, roadway layout, the grillage meshes, supports, and the longitudinal and transverse beam definitions.
00:51
All that remains now is to apply the loading.
00:54
Now, Structural Bridge Design includes all the necessary bridge loading types.
00:59
However, in order to circumvent the need for any manual entry of dead or superimposed dead loading, there is a tip we can use.
01:10
If we quickly open the file we used for the preliminary design where we used the line beam method,
01:16
we can see that there were some automatically generated dead loads.
01:20
All we need to do is remove the live load entries and then export what is left to a load file.
01:27
This can then be used back in the refined bridge model.
01:40
To use those saved loads, we can just navigate to the correct beam and import the loading.
01:48
We can now see that we have dead and superimposed dead loading for that beam.
01:52
We can now proceed to the live loading.
01:56
The process of generating the live loads is via a live load optimization, guided by influence surfaces.
02:04
Once the influence surface generation panel is active,
02:08
the designer chooses the beam that will be the focus of the influence surface generation, then configures the effects and scope required.
02:18
We will keep this simple for the example, but for actual bridge work, this list could be extensive.
02:25
Once the influence surfaces are generated, it is easy to see the effect of loads placed on the beam, not only for the beam itself,
02:32
but for the whole structure.
02:35
With this knowledge, the designer can press on to the actual load optimization.
02:39
This process is codependent, and the designer will choose which limit states to satisfy, together with other critical criteria.
02:47
Once the loading patterns have been established, the model can then be analyzed, and the results explored.
02:55
Once in the results viewer, the view will need to be configured in a number of ways in order to be able to examine the relevant data.
03:05
In our example, we will be looking for envelope result types relevant to the specific beam we are interested in.
03:13
This is done by manipulating the drop-down lists at the top of the viewer,
03:17
then by filtering the model so as only to reveal those results of interest.
03:22
We can then see the table of results.
03:25
However, it may be interesting to the designer to gain a little more insight into the makeup of each of the values.
03:32
This can be done by using the Drilldown feature, which will reveal the makeup of each value together with any factors used.
03:41
Now that we have the analysis results, we can transfer those over to the beam in question.
03:47
Once completed, we can see that they have now joined the dead loads from earlier and we can proceed to the beam design.
03:55
The beam design is carried out in a very visual manner
03:59
using a stress plot as a guide together with the various low cases that the designer is considering.
04:06
The stress plot is basically a plot of the compressive stresses in the concrete,
04:11
and these are shown by the red and green curves denoting failure or success respectively,
04:17
and the blue lines displaying the limits from the design code.
04:21
In order to reduce the concrete stresses to an acceptable level, the designer is able to invoke a tendon optimization.
04:29
The designer chooses the criteria for the optimization,
04:33
which will include whether the beam is to be symmetric and whether to consider debonded or halved tendons,
04:39
together with a variety of other controls, including comparative costs for the various tendon layouts.
04:46
A generative design process then ensues and after all options are considered, the least-cost workable solution is presented.
04:55
This solution can then be tested against the other cases.
04:60
The fully formatted design reports for any point along the length of the beam can be generated and explored at any time
05:08
in both text and PDF formats.
05:13
If, for any reason, the designer feels the need to make changes to the automatic design,
05:18
it is possible to manually interact with the tendon layout directly for full control of the design.
05:28
During the design process, it is usual to iterate many times on any given design, and more critically for steel section designs,
05:37
the designer will need any design changes made in Structural Bridge Design to be reflected within the InfraWorks model.
05:45
We can see in this example that the steel beam is failing and the designer will need to examine the design in Structural Bridge Design
05:54
in order to identify the exact cause and find a solution.
05:59
Once the designer has explored the results and interacted with the design, the way forward in this case
06:06
is to make some minor changes to the steel section.
06:11
To achieve this, the designer uses the beam definition forms to make a small change in depth,
06:18
as well as a change to the thickness of the bottom flange.
06:23
With the design now working, the Structural Bridge Design file is saved.
06:28
Then, back in InfraWorks, update from ASBD is used to bring the still section changes back into the InfraWorks model.
06:47
In this last section, we will examine how we can use the automatic refined analysis model generation
06:54
to create a full, finite element model of a tub girder arrangement.
07:00
The generation process is very similar to that used for the grillage model,
07:05
except that the designer chooses Tub girder under the analytical model type.
07:11
Again, the controls need to be quickly configured and an option as to whether a hybrid grillage FE model is required.
07:21
In this case, a hybrid model was requested.
07:24
When the generation is complete, the resulting model can be previewed, then loaded into Structural Bridge Design.
07:31
As with the grillage model earlier, all the necessary parts of the model are there, including the alignment and road layout.
07:40
The loading process is also similar to that which we have already seen earlier, and in this case,
07:45
we will test the integrity of the FE model with the built-in test loads.
07:51
Once the analysis has taken place, the designer can then, as before, use the results viewer to see the outcome of the analysis.
00:04
Following on from our preliminary design using the line beam analysis, we are going to generate, automatically,
00:10
a complete grillage model.
00:14
Using the refined analysis option, we can configure how the grillage is to be generated.
00:21
Once the generation has been completed, we can then preview the results and load the model into Structural Bridge Design.
00:33
In this example, the first three spans were chosen for generation, and we can see that all the necessary parts are available,
00:40
including the alignment, roadway layout, the grillage meshes, supports, and the longitudinal and transverse beam definitions.
00:51
All that remains now is to apply the loading.
00:54
Now, Structural Bridge Design includes all the necessary bridge loading types.
00:59
However, in order to circumvent the need for any manual entry of dead or superimposed dead loading, there is a tip we can use.
01:10
If we quickly open the file we used for the preliminary design where we used the line beam method,
01:16
we can see that there were some automatically generated dead loads.
01:20
All we need to do is remove the live load entries and then export what is left to a load file.
01:27
This can then be used back in the refined bridge model.
01:40
To use those saved loads, we can just navigate to the correct beam and import the loading.
01:48
We can now see that we have dead and superimposed dead loading for that beam.
01:52
We can now proceed to the live loading.
01:56
The process of generating the live loads is via a live load optimization, guided by influence surfaces.
02:04
Once the influence surface generation panel is active,
02:08
the designer chooses the beam that will be the focus of the influence surface generation, then configures the effects and scope required.
02:18
We will keep this simple for the example, but for actual bridge work, this list could be extensive.
02:25
Once the influence surfaces are generated, it is easy to see the effect of loads placed on the beam, not only for the beam itself,
02:32
but for the whole structure.
02:35
With this knowledge, the designer can press on to the actual load optimization.
02:39
This process is codependent, and the designer will choose which limit states to satisfy, together with other critical criteria.
02:47
Once the loading patterns have been established, the model can then be analyzed, and the results explored.
02:55
Once in the results viewer, the view will need to be configured in a number of ways in order to be able to examine the relevant data.
03:05
In our example, we will be looking for envelope result types relevant to the specific beam we are interested in.
03:13
This is done by manipulating the drop-down lists at the top of the viewer,
03:17
then by filtering the model so as only to reveal those results of interest.
03:22
We can then see the table of results.
03:25
However, it may be interesting to the designer to gain a little more insight into the makeup of each of the values.
03:32
This can be done by using the Drilldown feature, which will reveal the makeup of each value together with any factors used.
03:41
Now that we have the analysis results, we can transfer those over to the beam in question.
03:47
Once completed, we can see that they have now joined the dead loads from earlier and we can proceed to the beam design.
03:55
The beam design is carried out in a very visual manner
03:59
using a stress plot as a guide together with the various low cases that the designer is considering.
04:06
The stress plot is basically a plot of the compressive stresses in the concrete,
04:11
and these are shown by the red and green curves denoting failure or success respectively,
04:17
and the blue lines displaying the limits from the design code.
04:21
In order to reduce the concrete stresses to an acceptable level, the designer is able to invoke a tendon optimization.
04:29
The designer chooses the criteria for the optimization,
04:33
which will include whether the beam is to be symmetric and whether to consider debonded or halved tendons,
04:39
together with a variety of other controls, including comparative costs for the various tendon layouts.
04:46
A generative design process then ensues and after all options are considered, the least-cost workable solution is presented.
04:55
This solution can then be tested against the other cases.
04:60
The fully formatted design reports for any point along the length of the beam can be generated and explored at any time
05:08
in both text and PDF formats.
05:13
If, for any reason, the designer feels the need to make changes to the automatic design,
05:18
it is possible to manually interact with the tendon layout directly for full control of the design.
05:28
During the design process, it is usual to iterate many times on any given design, and more critically for steel section designs,
05:37
the designer will need any design changes made in Structural Bridge Design to be reflected within the InfraWorks model.
05:45
We can see in this example that the steel beam is failing and the designer will need to examine the design in Structural Bridge Design
05:54
in order to identify the exact cause and find a solution.
05:59
Once the designer has explored the results and interacted with the design, the way forward in this case
06:06
is to make some minor changes to the steel section.
06:11
To achieve this, the designer uses the beam definition forms to make a small change in depth,
06:18
as well as a change to the thickness of the bottom flange.
06:23
With the design now working, the Structural Bridge Design file is saved.
06:28
Then, back in InfraWorks, update from ASBD is used to bring the still section changes back into the InfraWorks model.
06:47
In this last section, we will examine how we can use the automatic refined analysis model generation
06:54
to create a full, finite element model of a tub girder arrangement.
07:00
The generation process is very similar to that used for the grillage model,
07:05
except that the designer chooses Tub girder under the analytical model type.
07:11
Again, the controls need to be quickly configured and an option as to whether a hybrid grillage FE model is required.
07:21
In this case, a hybrid model was requested.
07:24
When the generation is complete, the resulting model can be previewed, then loaded into Structural Bridge Design.
07:31
As with the grillage model earlier, all the necessary parts of the model are there, including the alignment and road layout.
07:40
The loading process is also similar to that which we have already seen earlier, and in this case,
07:45
we will test the integrity of the FE model with the built-in test loads.
07:51
Once the analysis has taken place, the designer can then, as before, use the results viewer to see the outcome of the analysis.
