PTQ Gas 2022 Issue

tions were modelled. The tempera- ture change (ΔT) = ±40°C was used for steel members. Horizontal fric- tion and anchor forces at start-up and shutdown conditions were also considered. The maximum beam vertical deflection is calculated as (δ max ) =14.6mm. The allowable beam ver - tical deflection is (δ v )=17.5 mm. The steel module sway deflection was calculated at several elevations to assure compliance with the ser- viceability limit state. The maxi- mum sway deflection was found as (δ Hmax ) =61mm. The allowable sway deflection was minimised to avoid excessive lateral deflection that may impact equipment function- ality. The largest lateral deflection was (δ H ) Limit =63mm. The utilisation ratio index (UI) was calculated for service limit state (SLS) and ulti - mate limit state (ULS) conditions to confirm compliance with CSA-S16 requirements. The maximum SLS unity index is (UI) SLS =0.84 and (UI) ULS =0.88. Figure 4a shows the founda- tion pile cap layout for SM-01. The dashed circles denote concrete pile locations. For the erection condi- tion, the maximum SLS column reaction was found as (P) max =616 KN, maximum shear reaction (Q) max =78 KN, and (T) max =0. The criti - cal columns for compression and shear forces are identified in Figure 4a . Maximum ULS column reaction for the steel module was found to be (P) max =827 KN and the maximum shear reaction was (Q) max =99 KN. Section A-A through the pile cap is shown in Figure 4b . The pile cap thickness used in this numer- ical model is 0.6m. The steel skid of the module SM-01 is partially embedded in concrete to minimise the vibration effect induced during operation. The vertical pile rein- forcements are projected into the pile cap. The maximum FE pile cap moment is (M max ) =120 KN-m/m. The recommended pile cap rein- forcement is shown in Figure 4b . The factored pile cap shear resist- ance is (V c )= 1703 KN > 827 KN. The nominal pile diameter used is 750mm and the maximum pile length is 20m. Upon installation, the pile head is treated as free headed

A

B

1

2

Z

Z

2m

7m

5m

2.6m

2.6m

PF1

PF2

M

M

1m

Splice joint

5m

M

M

4m

Splice joint

M

M

5m

5m

X

Y

1

B

(O)

(O)

(a) Elevation A

(b) Elevation B

Figure 3 SM01 structural elevations

three sub-modules (M1, M2, M3) and was assembled on-site using heavy lift cranes. The envelopes of these modules are shown in Figure 3 as dashed rectangles. Pipelines, cable trays, and mechanical equip- ment were installed and commis- sioned in the fabrication yard and transported to the site. Four lifting points were used on each module. Orange represents M1, yellow M2, and green M3. SM-01 numerical simulation The structure was modelled using 568 (2D) elements with a total of 7043 degrees of freedom (DOF). Equipments and vertical piping loads for empty, operational, and testing conditions were considered. Thermal loads (TL) arising from contraction or expansion of the members due to temperature varia-

on this level. A small platform is placed on the longitudinal beams to facilitate maintenance access dur- ing shutdown. Grating with vertical pipe penetrations were reinforced for holes larger than 300mm in diameter. Figure 3a shows structural eleva- tions along grid line 1. Cantilever platforms are used at levels (z)=5 and 10m. Vertical bracings reduce tip deflections. A wide bracing pattern is used at frame in the two levels to maximise the access area required for maintenance. Figure 3b shows the frame elevation along grid line B. The module along this grid line consists of three levels. Splice joints are also shown on this elevation. Steel framing is con- nected to primary beams at (Z)=5m to support interior equipment. The steel module SM-01 is divided into

1

2

5m

4m

Z

15M @ 150mm 15M @ 150mm

B

2m

0.6m

(P) max

15M @ 200mm

A

A

20-30M

7m

15M @ 200mm

(Q) max

B

B

20-30M

A

X

(a) Pile-cap layout

(b) Section A-A

(c) Section B-B

Figure 4 SM-01 foundation plan and details

34 Gas 2022

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