The trouble goes on and on...

The amendments on UNIMAS roof truss continues, The model of the tie truss was constructed. It was then attached to the main truss. Additional trusses were constructed to support the metal roof that was on both side of the main truss.

Supports that resist vertical load were assigned at node 2,173,88,43,214,129,55,226,141,482,426,484,483,463 and 485. Dead load of 0.5kN/m^2, live load of 0.25kN/m^2 and wind load of 1.0kN/m^2 was assigned. The model and analysis was completed on the day.

The completed model and analysis of the UNIMAS roof truss was checked by Mr. Siva. Corrections listed as below was required:

-An additional member was required for the main truss to complete the triangular looks of main truss.
-I-beam was assigned to the trusses that supports the metal roof that is on both sides of the main roof.

-The beam sections were standardized by limiting the amount of beam sections used.

Corrections were completed on the day.

An overview of UNIMAS roof truss

The plane view of UNIMAS roof truss

loads were assigned to the roof truss

The deflected shape of the roof truss

Wrong assumptions

The analysis for pedestrian bridge was checked by Mr. Goh. Two mistakes were specified by him. First, the bridge was assumed to be straight instead of tilted, was completely wrong. Second, there is an additional loading on the bottom chord of the main truss, due to selfweight of the concrete and aluminum box.

First attempt was made to model the bridge based on the coordinate obtained from the autocad drawings provided. Sadly, it yields an irregular shape. Without much hesitation help was seeked from Mr. Lim. he advised me to make things simpler by rounding up the numbers and use cos-sin-tan method to obtain the coordinate. The corrections and analysis was completed on the day.

The end is futher than I thought

I was informed by Mr. Siva that the design of the UNIMAS roof truss has been revised based on the passed meeting with the appointed architect. The changes made are:

- The cross section of the main truss is triangular instead of a vertical line. However, the main truss that is in between the other two reamins as before.

- The fascia truss was eliminated.

- Formation of the tie truss changes as well. Top-chord of the tie truss extrudes 1m from the main truss, while bottom-chord extrudes 0.5m from the main truss.

- The existing canopy has been changed to metal roof.

- Tie-truss and I-beam was added to support the metal roof.

The drawings of the above changes were not provided by the architect. It was mere verbal instructions. As for today, I managed to model the triangular chaped main truss.

The main truss was changed to triangular shape

Pedestrian bridge

I was assigned by Mr. Goh to conduct an analysis on 2 of the pedestrian bridges that is made of steel, located at seksyen U8, Bukit jelutong, Shah Alam. I was then informed by Mr. Goh that the plan view of the provided drawings is up to date, while the elevation view of the provided drawing is not. However, the plan view of the pedestrian bridge 1 does not match the elevation view. As a reason. It was put on hold for a moment. The coordinate of pedestrian bridge 2 was located with help of Autocad.

The next day, the model of the pedestrian bridge 2 was constructed based on the coordinate obtained. Through my disappoinment, the bridge does not appear to be straight. Help was seek from Mdm. Tan, one of the reputable draughtsman in the consultant firm. I was advised by her to model the bridge as if it is straight, instead of tilted. The model of the bridge was completed on the day.

The analysis continues, dead load assigned is 2kN/m, while live load assigned is 4kN/m. The beam section assigned for top-chord and bottom chord of the bridge is SHS 150x150x8.0. On the other hand, the middle chord made up of SHS 150x150x8.0 and CHS 76x5.0. As for the column, beam section of CHS 324x6.0 was assigned. The supports at column resist translational and rotational movement. While, supports that is located at the end span of the bridge only resists vertical load to allowed expansion and compression of the steel bridge due to influences of heat.

After consucting the analysis. It yields a maximum deflection of 14.04mm at node 25. based on the analysis, plane flexuaral buckling and lateral torsional buckling is adequate. Checks for axial stress for each member is adequate.

An overview of pedestrian bridge 2

The deflected shape of the bridge

Analysis completed

Arrived early in the morning, segments of roof truss which consists of main truss, fascia truss and tie truss was combined. Beam section of 152x6.0 was assigned to the middle chord of the main truss. On the other hand, beam section of 102x3.0 was assigned to the top chord and bottom chord of tie truss and beam section of 76x5.0 was assigned to the middle of tie truss. Supports that resists vertical translational motion were located at node 114, 58, 2, 155, 99, 43, 167, 111 and 55.

The analysis yielded a maximum deflection of 21.94mm at node 189. Based on the analysis, plane flexural buckling and lateral torsional buckling check is adequate. Checks for axial stress for each member is adequate.

An overview of UNIMAS roof truss

The deflected shape of UNIMAS roof truss

Super structures

At the begining of the week. I was assigned by Mr. Siva to analyse a roof truss of a amphitheatre that is located at UNIMAS Sarawak. Coordinate of the roof truss was provided by the respective draughtsman Mr. Azizi. Dead load assigned was 0.5kN/m^2 and live load assigned was 2.0kN/m^2, while point load due to canopy was Fy = 100kN and Fx = 173kN. Wind load assigned was 1 kN/m^2.

As for today, Main truss, fascia truss, tie truss 1 and the tie truss 2 was modeled. Uniform distributed load was calculated for dead load, live load and wind load. It was assigned on the main truss and tie truss only, As a reason, tie truss only resists lateral stress. On the other hand, the loads due to the canopy was not able to calculate. Therefore, the load that acts on the roof truss was then estimated as Fy = 100kN and Fx = 173kN

The main truss

The fascia truss - The fascia truss and main truss may looks alike but they are different in terms of loads that acts on it

The tie truss that attaches to main truss - tie truss resists lateral stress

Rare opportunity

Today, I was given an opportunity to design a canteen which is to be located at UTAR phase 2 by using ETABS.

First, I was advised to design the slab, then proceed to beam and finally the column. Besides that, I was also advised to design by manual calculation before proceed to computer aided design. The purpose of manual calculation is to determine the slab thickness, area of steel bars and numbers of steel bars provided. I was assigned to calculate slab A, slab B and slab C at various location.

Slab A was completed on the day itself. Characteristics of the slab as follows:

-Selfweight of slab = 3.6kN/m^2
-Dead load = 2.5kN/m^2
-Live load = 5.0kN/m^2
-Two way slab
-Slab thickness = 150mm
-Nominal cover = 30mm
-High tensile Steel bar diameter = 10mm
-Support X and span X = 6T10-150mm and 5T10-190mm
-Support Y and span Y = 3T10-320mm and 3T10-320mm
-Deflection is satisfactory for span X and span Y

Disaster strikes

Today, I was assigned by Mr. Siva to tabulate a table on design schedule. Due to insufficient information, I will have to search for incoming files and outgoing files for the specific date of every design activity. Through my disappointment, the incoming files and outgoing files are too wide, in terms of information, it will takes days for me to browse through. Finally, I resort to the date based on project quality plan and it makes scheduling much easier. In the mean time, my computer failed five times while tabulating data. Thankful, I have manage to replace the computer with one that is in better shape.

Section properties

I was assigned by Mr. Alex to provide him with section properties for liftcore. It was not a simple task as to search for the section properties in the British Standard Manual for solutions. As a reason, a usual liftcore has irregular shape. Therefore, Computer software such as Prokon is vital to generate the section properties for the liftcore based on the dimension provided.

The section properties of service lift A at ground level