Rizhao artifact
I didn't take the sunshine calculation seriously before, and I felt that there was no technical content. Now I realize that it is still too young and the sun is too fucking tormented. Based on the principle of throwing the devil to the extreme, I spent some time studying sunlight. Before it's too late, I'll put an artifact first.
This thing is called sunshine cone, which is used by all the people in the three-party evaluation unit, but few people in the design institute know that with it, sunshine calculation gets twice the result with half the effort, and you can't help but come back and boast.
This artifact is simple to say.
Suppose you stand on the roof of your house and bask in the sun. From 8 am to 4 pm, you haven't moved all day. So, what are the elevation and horizontal angles of the sun shining on you at all times? This angle does not need to be calculated or known. You just need to know the shape of the light in these eight hours.
This is a truncated cone.
Suppose you want to spend an hour in the sun at noon, then the shelter can't block the light too much.
Seen from the horizontal plane, at least 15 light is not blocked. 24 hours a day, the sun rotates at an angle of15 per hour. This kind of light passing through the side of an obstacle is called side light.
Seen from the cross section, the height of the obstacle within 15 should be less than the height of the light at the position where the obstacle is located, so that the light at the top of the obstacle can pass through, which is called top light.
In this way, the light can shine on you unscrupulously through the gaps in these barriers.
Suppose you want to get sunshine at other times? The principle is the same, as long as the skin of this cone is not blocked horizontally and vertically.
If you already know the usage of the sunshine cone, and you can draw inferences in the project, then you don't need to read the following.
Here I will explain the manufacturing method and application of sunshine cone, especially the superposition application of sunshine cone under complex conditions, in order to find a solution to maximize the floor area ratio under extremely unfavorable sunshine conditions.
How to get a sunlight cone
In order to calculate the angle conveniently, we divide this cone into 16 parts, each part is 7.5, which is half an hour. You can do it in minutes if you like, but I don't recommend that.
It should be noted that there are obvious errors in this simple dichotomy, and how the specific errors are generated is a mathematical problem, which is beyond our discussion. I suggest you use an accurate sunlight cone and generate it directly by software. I just want to briefly explain the principle here.
The sunlight cone is divided into 16 equal parts, once every half hour. The sunshine tube itself has errors, so you can probably count the squares when using it, and it is more reasonable to take it once every half hour.
The sunlight cone is divided into 480 equal parts, each of which is 1 min. If you want to play like this, who cares? .
However, I prefer to use software to generate directly. This picture can strongly prove where the obvious mistakes are, hehe. ...
This figure was generated by Tsinghua Building Sunlight Analysis Software. It is a three-dimensional vertebral body. Next, I will import it into sketchup for research.
This is the shape of the sunlight cone imported into sketchup.
After that, we turned to the side elevation and divided the sunshine cone into 10 sections according to the section of 10 m, which means that we only take the effective sunshine cone below 100 m, which is rarely used in redundant daily work.
The side view divides the sunlight cone into two parts. The horizontal line spacing in the figure is 10m, and there is a *** 10. We can see that on the right side of the intersection of 100m horizontal line and sunshine cone, the height of the light is greater than 100m. Let's remember this conclusion.
It looks like this in three dimensions.
Looking at the sun cone we cut from the top view, the scale in the picture is from 8 am to 4 pm, and the redundant parts need to be deleted.
This is the cut sunshine tube, and I deleted the extra part.
One of the treatments in CAD is the sunshine artifact mentioned at the beginning of the article. The sunshine cone generated by Tsinghua sunshine software needs to be processed, while the red leaf sunshine software can directly generate the usable sunshine cone. For example, this is actually directly generated by red leaves, and I didn't deal with it honestly. Other sunshine softwares, such as Cizhi and Tianzheng, can also generate sunshine cones directly, and the form is similar. Please note that the longitude and latitude of each city are different, and its sunshine cone is different, so you can't mix them.
Let's look at the line of 100 meter, which is the bottom arc. Then, under the line of 100 meters, the height of light is greater than 100 meters. That is to say, I put a building with a height of 100 meters under the line of 100 meters, which does not block the top light, which is appropriate.
If I put a 100-meter-high building on the 100-meter line, the building will properly block the top light. At this time, the lighting point can only receive the side light of the building.
Please keep these two features in mind and we will use them in the case.
Case actual combat
Below, let's take an example to understand the application of the sunshine cone.
The shaded part in the figure is the project plot with a height limit of 80 meters. The buildings marked with red characters in the picture are the buildings that need to consider sunshine at present. We don't consider other requirements of boundary retreat and spacing, but only analyze what buildings can be built and how high they can be built in those places of this plot from the perspective of sunshine.
Import drawings into SketchUp and learn in 3D software for easy display.
This is a map that has been imported into su and processed. Gray buildings don't need to consider sunshine, and white buildings are our research objects. The upper line of the gray part at the bottom of the white building is the height of the window sill, which is exactly what we study. Vertical sunshine is not considered in this study for the time being.
This is a solar cone imported from SketchUp, which only keeps the epidermis of the vertebral body, that is, the light channel.
I numbered the buildings, and it takes a long time to analyze the 5# and 9# buildings in this way, so I put them in the final study.
This is the result of the current sunshine. 1#-3# The right side of the black vertical line meets the sunshine for two hours, and the sunshine between 1# red vertical line and black vertical line lasts for one hour, and the left sides of 2# and 3# black vertical lines meet the sunshine for more than two hours. So our new building can't reduce the sunshine now.
We put the sunshine cone at the most unfavorable sunshine point in 1# building. As can be seen from the figure, if there are no buildings in this plot, then this point only has more than one hour of sunshine, and we must ensure that it has at least one hour of sunshine to meet the requirements. The height of the building marked by the blue circle in the figure is 88.6m, which blocks most of the sunshine from 8:00 to 9: 00 (the second arc of the sunshine cone from bottom to top is 90m line, and most of the buildings are above the 90m line, so the light at the top of the building cannot pass through), so it is necessary to ensure that the sunshine from 9: 00 to10: 00 is not blocked, and at 8: 00,
Therefore, the building height within the range of 8: 00-9: 00 (green line and blue line indicated by yellow arrow in the figure) should be less than the arc height indicated by red arrow.
In SketchUp, we can see it more intuitively. The light in the red area is blocked by the existing building, and the light in the yellow area can reach this point. We only need to keep the sunshine duration at 1 hour, then the rightmost light channel which has the greatest influence on the building height of the plot can be abandoned.
Looking at the light channel from a three-dimensional perspective, the height of our new building is smaller than the yellow conical skin above.
We pull a piece to the lower surface of the optical channel and get a piece with this shape. That is to say, if a building of this shape is built in the plot without considering any specification conditions, the sunshine of 1# building will not be affected. I'll call this block for the time being.
Let's look at Building 2.
By the same token, find the effective light channel of Building 2 and determine the height of the buildable buildings in the plot. As can be seen from the figure, the effective optical channel is between 8: 30- 10: 30, and the sunshine duration is two hours.
Look at the light channel in SketchUp.
When we show Block A, you will find that Block A, which does not block 1# building, blocks 2# building. At this time, block A should be cut off to prevent it from blocking the 2# building.
The practice of determining the building height of a plot through the superposition of two or more sunshine cones is called the superposition application of sunshine cones.
The red part of block A in the picture is what we need to cut off. We also need to build other blocks affected by the light channel in Building 2.
1# and 2# buildings are blocks formed by optical channels. In the same way, we continue to study buildings 3#, 4#, 6#, 7# and 8#.
This is a block generated by comprehensively considering the influence of 1#, 2#, 3#, 4#, 6#, 7# and 8# optical channels, in which the height of the blank part of the basement is currently 80 meters (height limit). The reason why we don't build this split block is because we haven't considered the influence of the remaining 5# and 9# buildings.
Let's study the 5# building, and you can directly view the optical channel in SketchUp.
First of all, the solar cone is placed at the left end of Building 5, and we give priority to the light channel outside the plot to minimize the impact on the plot. As can be seen from the above picture, there are just two hours of optical channels from 12: 00 to 14: 00, and the impact on the plot is only a small part. If we consider the requirement of building retreat, the light channel at this point has no effect on the building height of our plot. As mentioned above, this study does not consider the influence of other specifications except sunshine, so I will still make the affected blocks.
This is a plane solar cone in CAD, and it is not difficult to find the most favorable light channel.
Of course, you can also use the optical channel between 8: 00-8: 30 and 12: 30- 14: 00. However, the optical channel between 8: 00 and 8: 30 personally thinks that it has too great influence on the plot, so this scheme is not adopted.
Then, we move the sunshine cone to the right end of Building 5.
The light passage outside the right-hand plot of Building No.5 can completely meet the sunshine requirement of 2 hours, so no matter how high the buildings in the plot are built, there is no sunshine influence on them.
Next, we put the sunshine cone in the middle of Building 5.
Give priority to the use of optical channels outside the cell. Based on the sunshine cone of three positions, this part of the north of our plot can be made 80 meters high, which is a good thing for the floor area ratio. Three solar cones are stacked together, and we make a building block.
You also found that there are some wastes at the north end of the block caused by the sunshine in Building 5, which is unreasonable. Finally, I will trim it uniformly. Next, we will study the sunshine in building 9, and the research method is the same as that in building 5, so I won't go into details here. I will succeed.
Then, this is the block we made according to the theory. I'll call it Block B for the time being. With it, we can determine the building height of each inch of land in the plot, and the planning of the maximum floor area ratio will be handy.
Because I took the screenshot according to the most unfavorable point, I will inevitably ignore the sunshine in many places, such as buildings 5#, 6#, 7#, 8# and 9#, which need the whole surface to meet the sunshine for more than 2 hours, but I only selected three points or even one point, and there will definitely be errors.
To give an obvious wrong example, we put the sunshine cone in the middle of Building 8.
The sunshine time here is less than 1 hour, so it needs to be cut again to meet its harsh sunshine requirements.
We have three options. Green, black and purple parts can be cut. There is no doubt that if the black part is cut off, nothing can be done with a small piece. After the black part is cut off, there will be 1.5 hours of sunshine in the middle of Building 8, so one of the green and purple parts must be sacrificed. How to choose, we need to consider the specification requirements such as building concession and building spacing, and find the scheme with the least loss.
We use the dotted line to indicate the exit boundary, and we find that there is just one more optical channel after the green part exits the boundary. Everyone is very happy.
In our actual project application, the situation will be much simpler than here. We only need to use the plane sunshine cone to calculate step by step. Of course, you have to remember or mark the height of each building clearly.
Finally, put the building in Block B according to the specifications.
As you can see in the picture, I didn't put the buildings exactly according to this block, and some of them were beyond the scope of block B. This is because according to the sunshine code, a household only needs one window to meet the sunshine requirements. Another reason is that the sunshine cone has errors, even the sunshine cone generated by the software itself has errors.
This is the general plan obtained by this method. We use the sunshine in Tsinghua to calculate the sunshine around us.
Externally, the sunshine of the existing buildings is met and partially reduced, but the windows are not affected, which is also considered to meet the sunshine requirements.
In practical engineering, the superposition application of sunlight cone is far from so complicated. We only need to place the building according to the height line of the sunshine cone, which will directly adjust the height or length of the building in the scheme. In order to let everyone see it more intuitively, I explained the overlapping cutting phenomenon of sunlight cone and building blocks in SketchUp.