TowerPeak

CONTENT TITLE

Part I

“TowerPeak-1”will include all floor slabs, walls, columns and beams as individual members to perform structural analysis as a single run. Each nodal point is to allow for six degrees of freedom. For line members such as column and beam, analysis will be based on classical structural analysis method. For floor slab & wall members, analysis basing on finite element method will be adopted (these members are to be taken as thick plate elements). Modeling a building structure in such a way, results of high degree of accuracy and consistency can readily be expected. Other further simplifications, assumptions and analogy types of modeling, will become unnecessary. In addition, localized actions and effects can readily be reflected as well. With the aid of AutoCad (a popular drawing software), any geometrical shapes can be inputted into TowerPeak-1. This feature is useful for input information such as cross-section of elements (such as slabs, beams, columns, walls and etc).ores load patterns (such as area or point load) acting on slab element. Actually, graphical information can be transferred (import or export) between TowerPeak-1 and AutoCad. As a result, under the setting of AutoCad, TowerPeak-1 can generate graphical output (or results) such as 2-D plan, 3-D plan, beam & column schedule drawing, Rebar drawing and many others. In short, the main features of TowerPeak-1 can be summarized as follows:- I. The principal technique of “TowerPeak-1” is to utilize the structural stiffness of every floor sub-system as an entity for analysis. The intermediate analyzed results will then be “re-inputted” into the full building global analysis to calculate another sets of intermediate displacement and internal force. The process will continue by iterations until difference of subsequent sets of result have become sufficiently small. Doing structural analysis in such a way, the objectives to have quick speed and high precision can readily be fulfilled. II. “TowerPeak-1” adopts space modeling. It is achieved by modeling floor slab & wall as shell elements with multi-sides and beam & column as line elements. The shell & line elements will then be analyze in a space setting. With the exceptions that slab has to be horizontal and wall has to be vertical, “TowerPeak-1” does not need to work with other structural simplifications or unusual assumptions. Even these restrictions on slabs & walls are expected to be eliminated in the coming revision in the near future. As a result, the computer structural model being established in “TowerPeak-1” can be perfectly matched with the physical structure. It means that one and only one model can be established for any given building structure. It will make data input and interpretation of output results much more easily. It is worth nothing that models in “TowerPeak-1” can include certain unusual structural features such as openings on floor slab, uneven thickness of wall, penetrations on walls, wall of linearly varying thickness and etc. Making use of the powerful features of “TowerPeak-1”, the following not so usual structural configurations are just a few examples which it can readily handled:-

1. Building with Multi-Towers (see Fig 1.1.1) 2. Shear walls slab having arbitrary shaped openings (see Fig 1.1.2) 3. Split-levels (see Fig 1.1.3) 4. Stepped footings or pile caps (see Fig 1.1.4) 5. Slender columns at lower level not connected with floor slabs (see Fig 1.1.5) 6. Floor slabs of irregular shapes 7. Shear wall having cross-section of any arbitrary shape 8. Mega-braces, transfer plate and transfer floor/truss (see Fig 1.1.6), These structural configurations are complex. Using traditional software’s, it may require to make significant structural simplifications to enable an analysis can be performed. In addition, the requirement of computer hardware and running time may also be very stringent. Thanks to its swift algorithm, using “TowerPeak-1” to do analysis & design for these complex configurations, it only requires a normal PC computer and 10 minutes strong of computer’s running time. With new generations of PC computer which becomes more and more powerful, the running time for even those largest and most complex high-rise building structure can be shortened to an very agreeable level. It can be expected that “TowerPeak-1” will become a necessary tool for any structural engineer who does building design. Following are Figures 1.1.1 to 1.1.6:-

Fig 1.1.1 – Building with Multi-Towers

Fig 1.1.2 – Standard Storey Plan (note Openings on Walls)

Fig 1.1.3 Building having Split-levels

Fig 1.1.4 Stepped footings or pile caps

Fig 1.1.5 Slender columns or walls not connected with floor slabs

Fig 1.1.6 Transfer floor

In respect of structural dynamic analysis, “TowerPeak-1” also adopts space modeling which will have lumped mass assigned at nodal points. To have more accurate result, it is not simply taken every level as a single lumped mass (nodal point). In contrast, it takes the “actual” connection points of the upper/lower level elements (such as the point between column top/beam soffit) as nodal points having lumped mass. The mass of other elements will be “lumped” to those mass nodal points by static equivalent approach. As a result, the torsion couple will automatically be allowed for (because of the effect of space mass-nodal- point). To analyze frequent seismic events, “TowerPeak-1” can use either response spectrum method or linear time history method (based on mode decomposition) for the horizontal and vertical directions respectively. IV. An added advantage of “TowerPeak-1” is for underground basement. The basement of a building can be simplified by inputted as part of the global building structure. It makes data input and output interpretation much more direct and easy. Thanks to the features that loads (such as earth pressure or ground water pressure) can be inputted to wall stems and spring supports can be assigned to any floor levels. Basement can be simply inputted as wall stem system with loads acting on them. V. The programming procedure for “TowerPeak-1” is ground breaking. In addition to the swift algorithm for structural analysis, it utilizes the advantage multi-tasking and multi-threading (by using a number of sub-programs simultaneously). As a result, full potential capacity of nowadays PC’s powerful CPU is being made use to increase computation speed. VI. Thanks to the technology breakthrough, computation speed can be kept even with the high precision being achieved. For example, the computer running time required for a typical 45-levelled single tower building, designed for frequent earthquake events, will take only about 80 minutes to complete a full structural analysis and design. Noting that the scale of the computations; - number of nodes = 45x(495+145*4)+495 = 48870 &total degrees of freedom to be considered =48870x6=293220; VII. Other important features, which “TowerPeak-1”processes, include the followings:

1. To perform analysis for construction phasing for building (multi-tower types of building, for example) as a whole,

2. To compute for most unfavorable live load combination by separation of individual floors,

3. To do meshing (for finite element method) for the whole building structure automatically. No additional manual adjustment is required,

4. To calculate wind load effect automatically,

5. To extract relevant results automatically. For example, critical values can be extracted and then outputted (and displayed) overlaying on floor plan for easy interpretation by User,

6. To assign arbitrary shape of cross-section of any members, members can be made of different construction materials (such as structural steel section or reinforced concrete),

7. To do Re-bar design for any of the abovementioned cross-sections,

8. To adjust beam sizing after completion of analysis on load case combination,

9. To work out Bill of Quantities quickly and accurately,

10. To allow import of data files generated by other popular software’s, such as ETABS. Taking this feature, there will be no need to re-input structural information to “TowerPeak-1” if an existing

input file already exists. In summary, the main advantages of using “TowerPeak-1” are:-

10.1. Reduction of design effort and time significantly. Thus, both cost & timeframe to complete a building structural design can be greatly reduced.

10.2. Provision of substantial assistance to achieve Client’s building design requirements. Design restrictions due to complexity of structural configuration, such as split flooring, irregular floor plans, and limitations on opening shapes on slab or shear wall, will no longer hinder a structural engineer from fulfilling his Client’s intention. It is because “TowerPeak-1” can tackle these design issues in a highly efficient and effective manner. Lastly, “TowerPeak-1” (i.e. the superstructure module) has successfully obtained approval and certification from Hong Kong Buildings Department, Hong Kong SAR Government. The registration no. is S0634.