My Happy Ending

Today, was the last day of my internship. It ended with a farewell tea session with my colleagues and supervisor.

Detailing and optimizing

Today, I did detailing for Main Truss A, Main Truss B, Main Truss C, Tie Truss 1, Tie Truss 2, Box Truss 1, Box Truss 2, Box Truss 3, Box Truss 4 and Box Truss 5 by seperating each of it to plan view, elevation view, side view and finally 3 dimension model. The purpose of detailing is to ease draught works.

Optimisation was conducted and lower tie truss requires to reduce in section size, hence, section assigned was changed.

A few senarios were required for the analysis. First senario, one of the support was fixed and the other was free to move. After conducting the analysis it yields huge deflection. Second senario, both of the supports were free to move. After conducting the analysis numerous member failed due to buckling checks, hence, correction was conducted on the particular member that failed.

An example of detailing for Box Truss 1

A different approach

I was taught by Mr. Lim to calculate the loads that act on UTAR Grand Hall. Based on architect's drawings. Top chord made up of roof tiles, asbestos, purlins and more. Therefore, the dead load assigned was 1.0kN/m^2 and the live load assigned was 0.25kN/m^2. On the other hand, the dead load assigned for bottom chord was 1.95kN/m^2 and live load assigned was 4.00kN/m^2. As a reason, catwalk hangs directly under the main truss. However, dead load assigned at Box Truss 1 was 3.5kN/m^2 and live load assigned was 3.5kN/m^2. Such a huge different was mainly due to fly galleries.

Loads were calculated based on Microsoft Excel. An example of calculation of loads that acts on top chord:

Nodal load = 1.0 * ((2.114/2)+(2.360/2))*8.0
= 17.896kN

Loads were assigned to Main Truss A.

The first analysis was conducted and it yields a deflection of 76.59mm. Moreover, numerous members failed for lateral torsional buckling and plane flexural buckling. Problem was rectified, it was found that top chord was too thick, hence the next analysis was conducted it is fine.

Today, loads were assigned to the 2 dimension model of Main Truss A, Main Truss B and Main Truss C. Loads were calculated with the help of Microsoft Excel. Then checks for axial stress, lateral torsional buckling and plane flexural buckling was conducted and section assigned was adequate. After that, loads for Main Truss A, Main Truss B and Main Truss C was assigned to the 3 dimension model. Lastly loads were assigned to rafter.

Loads were assigned to the 2 dimension model of Box Truss 1, Box Truss 2, Box Truss 3, Box Truss 4 and Box Truss 5. Loads were calculated with the help of Microsoft Excel. After that, loads for Box Truss 1, Box Truss 2, Box Truss 3, Box Truss 4 and Box Truss 5 was assigned to the 3 dimension model. Supports were assigned to the 3 dimension model. Checks for axial stress, lateral torsional buckling and plane flexural buckling was conducted and section assigned was adequate.

Loads were assigned to the 3 dimension model of Main Truss A

Loads assigned to the 3 dimension model of UTAR Grand Hall

The model of UTAR Grand Hall was completed

The model of UTAR Grand Hall continues, the ridge was modeled and combined with the previously modeled main trusses, tie trusses and box trusses.

The section assigned as below:

Ridge(RDG) : 457x152x52 I1(I-beam)

Ridge bottom chord : 200x200x50 S1(SHS)

Second day of the week, the rafter was modeled and assigned to the previously modeled UTAR Grand Hall.

The section assigned as below:

Rafter(RFT) : 356x171x45 I1(I-beam)

The legend of UTAR Grand Hall was made for future reference. I was then assigned by Ms. Winnie to prepare the next meeting minute which will take place on 5th July 2010. Once the model of UTAR Grand Hall completed, I was taught by Mr. Lim to calculate and assign loading to the model. This time around, the approach of assigning loading is different. Point load was used instead of Uniformly distributed load. As a reason, UTAR Grand Hall has a very complex roof truss

The completed model of UTAR Grand Hall

I am one step closer to the completed model

Today, the model of Box Truss 1, Box Truss 3 and Box Truss 5 was completed. All three box trusses consist of bottom chord(BC), top chord(TC), horizontal(H),vertical(V) and diagonal(D). However, Box Truss 5 consists of an additional middle chord(MC).

Section assigned as follows:

Bottom chord(BC) : 305x305x97(H-section)

Top chord(TC) : 356x368x129(H-section)

Middle chord(MC) : 356x368x129(H-section)

Horizontal(H) : 203x203x46(H-section)

Vertical(V) : 203x203x46(H-section)

Diagonal(D) : 203x203x46(H-section)

The following day, model of Box Truss 2 and Box Truss 4 was completed. Both of the box trusses consist of bottom chord(BC), top chord(TC), horizontal(H), vertical(V) and diagonal(D). Section assigned was same as Box Truss 1, Box Truss 2 and Box Truss 3.

Before the day ends. I was assigned by Ms. Winnie to write a meeting minute for the up coming meeting. Once the meeting minute was completed, I was told to fax a copy to the people invited.

All box trusses were completed

The cover page of meeting minute

Soil Investigation

Today, I was given a rare opportunity to witness soil investigation at Denai Alam. Transport was not provided and I was not guided. Lecture notes on standard penetration test and wash boring was revised the day before to gain insight on soil investigation. When I arrived, technicians were conducting boring for borehole 2 and so I witnessed boring and standard penetration test.

I was interviewed the day after I came back from site visit. As a result, my superior found out that I was not very clear about standard penetration test, hence, I will have to return to the site to obtain borehole log, photos and videos as evidence. Borehole 3 was witnessed.

A sample of borehole log

Main truss and tie truss tied a perfect knot

Advise was seeked from Mdm. Tan. She strongly recommends that I obtain the coordinate from Main Truss A, Main Truss B and Main Truss C. It was done by splitting the main truss into two, connected with trusses in between and lengthen the lower truss of Tie Truss 1 and Tie Truss 2. The changes of Tie Truss 1and Tie Truss 2 was made by Hameen. After that, it was merged with Main Truss A, Main Truss B and Main Truss C. As a result, it matches perfectly.

The formation of box truss was analysed. After that, we found that the formation of Box Truss 1 differs from Box Truss 3. In terms of diagonal member. Box Truss 1 made up of bottom chord(BC), top chord(TC), horizontal member(H), vertical member(V) and diagonal member(D). The model of Box Truss 1 was completed today. Just like before, Box Truss 3 and Box Truss 5 made up of bottom chord(BC), top chord(TC), horizontal member(H), vertical member(V) and diagonal member(D). Box Truss 3 and Box Truss 5 was completed by today.

The tie truss was combined with main truss

Box Truss 1 was modeled