gantry crane report
TRANSCRIPT
EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCHORGANISATION EUROPÉENNE POUR LA RECHERCHE NUCLÉAIRE
CERN - SMB Department
EDMS Nr: 1715491 v.1Group reference: SMB-SE-FAS August, 2016
FUTURE CIRCULAR COLLIDER (FCC) CIVIL ENGINEERING
FCC GANTRY FOR DETECTOR LOWERING STUDY
DIMENSION ESTIMATES, POTENTIAL DESIGNS AND CONTRACTORS
J. CollinsApproved by:
John Osborne SMB/SE/FASHubert Gerwig EP/CMX/EI
Abstract
This report provides first estimates as to the size and cost of a gantry crane designed to lower a 6 000 tonne detector component approximately 200 - 400m underground. It also individualizes possible contractors to carry out its design.
SMB
EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCHORGANISATION EUROPÉENNE POUR LA RECHERCHE NUCLÉAIRE
CERN - SMB Department
1 INTRODUCTION
This work is done as part of the feasibility study of the FCC. As for the LHC, in-situ construction of the detectors (such as ATLAS) can be inconvenient as would have to be done 200 to 400m below ground and could delay the project up to five years. As an alternative, the detector is assembled above ground and then lowered into position. This requires a Gantry crane of significant dimensions and capacity (thousands of tonnes). Such a crane does not exist as a standard on the market and must be designed especially for the task.
2 INFORMATION COLLECTED ON CMS GANTRY CRANE (2000 TONNES)
2.1 General description
After the shaft was dug and constructed, a building was erected in which to assemble CMS to shelter and protect it and to mitigate noise pollution in the surrounding area. Four holes in the ceiling would allow the cables of the gantry crane, constructed around the outside of the building, to attach to the detector. Due to the presence of the building a fixed gantry cranes was designed to lower CMS and could only lift and lower loads. To displace the detector horizontally it was placed on a 1500 tonne concrete mobile platform that could slide horizontally by use of air pads and hydraulics jacks. (Osborne, 2006)
Figure 1: uncovered shaft and plug (Osborne, 2006)
Figure 2: Air pad (Osborne, 2006)
The platform, with the detector on it, was slid forward so as to act as a “plug” to the shaft down which the detector was to go down. Once the detector, weighing 2000 tonnes, was in position it was lifted off the plate by means of the gantry crane and the plug was returned to its original position, revealing the shaft below. The detector could then be lowered. (Osborne, 2006)
Figure 3: detector and plug slide forward (Osborne, 2006)
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Figure 4: Detector lowered into shaft (Osborne, 2006)
2.2 Raw data
2.2.1 Gantry dimensions
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Figure 5: Front view (VSL, 2006)
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Figure 6: Side view (VSL, 2006)
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Figure 7: design with load distribution (VSL, 2006)
2.2.2 Beam Cross section
The main beam has a total height of 3300mm, a web 1150 mm long and 50mm thick and a flange 2750mm long and 25mm thick. Stiffeners were used, labelled “Raidisseur” in Figure 8, with a width of 400 mm.
Figure 8: "I" beam cross section specification
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2.2.3 Lifting equipment
Figure 9: strand-jacker model used (weight specified) (VSL, 2006)
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Figure 10: Strand coiler model used (weight specified) (VSL, 2006)
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Figure 11: Hydraulic pump 1 used (weight specified) (VSL, 2006)
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Figure 12: Hydraulics pump 2 used (weight specified) (VSL, 2006)
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3 INFORMATION REGARDING DETECTORS TO BE LOWERED (FCC)
The detectors for the FCC are still in the process of being designed at the time this of this report and the data below dates from the 3rd of August 2016 (Mentink and ten Kate, 2016).
3.1 Unshielded Solenoid and Forward Solenoid
Table 1: Unshielded Solenoid and Forward Solenoid information (Mentink and ten Kate, 2016)
3.2 4T/10m Twin Solenoid and 4Tm Forward Dipole
Table 2: 4T/10m Twin Solenoid and 4Tm Forward Dipole information (Mentink and ten Kate, 2016)
3.3 4T/4-6m Thin and Transparent Solenoid
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Table 3: 4T/4-6m Thin and Transparent Solenoid information (Mentink and ten Kate, 2016)
4 MAIN BEAM ESTIMATES CALCULATIONS (DESIGN 1)
4.1 Assumptions
The general design remains the same as that of the CMS gantry crane: two large I beams supported by four columns each made of four I beams connected by bracing. Four strand-jackers apply four point loads, two on each beam.
As mentioned in (Desirelli and Ferreira, 2006) the two ‘HEA” profiles between the two large “I” section of the main beam were neglected. Instead, the two beam were considered separately and were assumed to carry half the load each due to the geometry of the structure and are thus of the same cross section.
The loads are assumed to be distributed as shown in Figures 13-14 and the shear force and bending moment follow the distributions shown.
Figure 13: Shear Force and Bending Moment distribution for applied loads
Figure 14: Shear Force and Bending Moment distribution caused from the beam self-weight
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4.1.1 Dimensions and equipment
The detector was assumed to have a diameter of 20 metres and to weigh 6000 tonnes. Based on the dimensions of the CMS gantry crane shown in Figures 5-7 (whose detector had a diameter of 15m) the following dimensions were roughly estimated:
Table 4: Gantry crane dimensions estimated for calculations
Column height 25mBeam span 30mDistance between two POI 20m
The main beam is to have two “I” beam profiles connected by an “HEA” profile. Four DL-S1672 type strand jacks weighing 12900 kg each when fully equipped are used and four Hydraulic power packs estimated to weigh 600kg each. Steel type S355 is assumed to be used.
4.2 Loads
4.2.1 Permanent Loads
Total permanent UDL on beam = self-weight of beam = weight/span = 983.8/30 = 32.793 kN/m
Total permanent action on beam = 2 Hydraulic power packs + 2 lifting units (DL-S1672) = 258 + 12 = 270 kN
4.2.2 Variable Actions
The variable UDL on the secondary beam = 30 000 kN
4.2.3 Combination of actions at Ultimate Limit State
ULS: Permanent + Variable*
At midspan:M max = 1.35 * (675 +3690) + (1.50 * 75000) = 118392 kNS = 0
At support:M = 0Smax = 1.35*(135+492) + (1.5*15000) = 23346
4.2.4 Design Values of Bending Moment and Shear Force
Smax = 23346 kN
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Mmax = 118392 kNm
4.3 Trial Section
Steel type S355 will be used. The nominal thickness (t) of the flange and web are between 40 and 80 mm.The yield strength is: fy = 335 N/mm2
4.3.1 Section Properties
Depth of cross-section h = 4100 mmWidth of cross-section b = 1600 mmDepth between fillets d = 3390 mmWeb thickness tw = 45 mmFlange thickness tf = 75 mmRadius of root fillet r = 30 mmCross-sectional area A = 4177.5 cm2
Second moment of area (y-y) Iy = 120000000 cm4
Second moment of area (z-z) Iz = 5123000 cm4
Radius of gyration, (z-z) iz = 35 cm Warping constant Iw = 4932.9 dm6
Torsion constant It = 57225.94 cm4
Elastic section modulus (y-y) Wel,y = 586957.1 cm3
Plastic section modulus (y-y) Wpl,y = 612286.1 cm3
Modulus of Elasticity E = 210000 N/mm2
4.4 Classification of cross-section
ɛ = √ 235f y
= √ 235335
= 0.8376
Outstand flange: flange under uniform compression
c = (b−t w−2 r )
2=
(1600−45−(2∗30))2
= 747.5 mm
ct f
= 74.875 = 9.967
The limiting value for Class 1 is ct f
≤ 9ɛ = 9*0.8376 = 7.538
9.967 > 7.538Therefore, the flange outstand in compression is not Class 1.
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The limiting value for Class 2 is ct f
≤ 10ɛ = 10*0.8376 = 8.3755
9.967 > 8.3755Therefore, the flange outstand in compression is not Class 2
The limiting value for Class 3 is ct f
≤ 14ɛ = 14*0.8376 = 11.726
9.967 <11.726Therefore, the flange outstand in compression is Class 3.
4.5 Bending Resistance of the cross-section
For a class 3 section the design resistance of the cross-section for bending about the major axis (y-y) is:
Mc,Rd = Mel,Rd = W el , Rd f y
γMO = 586957∗103 335
1 * 10-6 = 196631 kNm
M Ed
M c, Rd=118392
196631 = 0.6021 < 1.00 OK
4.6 Lateral torsional buckling resistance
4.6.1 Non-dimensional slenderness of an unrestrained beam
λ¿= 1
√C1* 0.9 λz √ βw
Where:
1√C 1
= 0.94
λz = Liz
= 3000035∗10 = 85.6677
λ1 = π√ Ef y
= π√ 210000335
= 78.617
λz = L
iz λ1 =
3000035∗78.617∗10 = 1.0897
√ βw= √ W y
W pl , y=1.0
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Therefore:
λ¿= 1
√C 1* 0.9 λ z √ βw = 0.94 * 0.9 * 1.0897 * 1 = 0.9219
4.6.2 Reduction factor for lateral torsional buckling
For I or H or equivalently rolled section
χLT = 1
φ¿+√φ¿2−β λ¿
2 but χLT ≤ 1.00 and χLT ≤1λ¿
2
Where:
φ¿=0.5¿)
λ¿ ,O = 0.4
β = 0.75
hb =
41001600 = 2.5625, where 2.0 < 2.5625 ≤ 3.1, we use buckling curve c for a rolled section,
with an imperfection factor αLT = 0.49
Therefore: φ¿=0.5¿) = 0.9466
And:
χLT = 1
0.9466+√0.94662−0.75∗0.92192 = 0.6873
Check:χLT = 0.6873< 1.0
χLT = 0.6873< 1λ¿
2 = 1
0.92192 = 1.1767
The reduction factor χLT = 0.6873
4.6.3 Modification of χLT for moment distribution
kc = 1
√C1 = 0.94
f = 1-0.5(1 - kc ) (1-2(λ¿ -0.8)2) but ≤ 1.0 = 1-0.5(1 – 0.94 ) (1-2(0.9219-0.8)2) = 0.9709
Modified reduction factor
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χLT,mod = χ< ¿f¿ =
0.68730.9709 = 0.7079
4.6.4 Design buckling resistance moment of the unrestrained beam
For class 3: Mb,Rd = χ¿
W El , y f y
γ M 1 = 0.7079∗586957∗103∗335∗10−6
1 =126534 kNm
M Ed
M b ,Rd =
118392126534 = 0.9356 < 1.0 OK
4.6.5 Shear resistance
Basic design requirement:
V Ed
V c ,Rd ≤ 1.0
Vc,Rd = Vpl,Rd = A v
f y
√3γ MO
For a rolled I-section with shear parallel to the web the shear area is:Av = A – 2btf + (tw + 2r)tf but no less than ηhwtw
Av = (4177.5*102) – (2*1600*75) + (45 + (2*30))*75) = 185625 mm2
η = 1.0 (conservative)ηhwtw = 1*(4100-2*75)*45 = 177750 mm2
185625 mm2 > 177750 mm2
Therefore, Av = 185625 mm2
The design shear resistance is therefore:
Vc,Rd = Vpl,Rd = 185625∗335
√31
*10-3 = 35902 kN
V Ed
V c ,Rd =
23346.3235902 = 0.6503 < 1.0
Therefore, the shear resistance of the section is adequate.
4.7 Serviceability Limit State
Vertical deflections should normally be calculated under the characteristic load combination due to variable loads, not including permanent loads.
The load combination at the Serviceability Limit State is:∑Gk + Qk,1 + ∑ψO,iQk,i
Modified by NA 2.23 to EN 1993-1-1 (Permanent loads not included).
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Only one variable action is present, therefore ∑ψO,iQk,I =0
4.7.1 Vertical deflection of beam
At mid-span, the vertical deflection is:
w = L3 Qk
26 EI y
∗¿
Qk = 30000 kN
w = 300003∗30000
2∗103
6∗210000∗1.2∗108∗104∗¿ = 32.155mm
Vertical deflection limit for this example is
span360
=30000360
=83.33 mm
32.155 mm < 83.33 mm
Therefore, the vertical deflection of the section is satisfactory.
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5 COLUMN ESTIMATES CALCULATIONS (DESIGN 1)
5.1 Assumptions
Each set of opposite columns carries half the load (therefore all the load from one of the two beams). Due to the geometry of the cranes each of these two columns will support half the load from one beam (a quarter of the total load).
The calculations outlined below follow the method used in the lifting gantry design report for CMS.
5.1.1 Dimensions and equipment
Table 5: Crane dimensions estimated for calculations
Column height 25mBeam span 30mDistance between two POI 20mLo 2.2mLm 2.0mLk 50m
The four beams that constitute the column are assumed to be I beams of the same cross section, Steel type S270 is assumed to be used.
5.2 Loads
5.2.1 Dead Loads
Tower self-weight: 378.56 kNHead piece on towers: 50 kNMain Beam: 250 kN Spreader beams: 250 kN
5.2.2 Live loads
Applied load: 30000 kN
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5.3 Effects of unfactored loads
5.3.1 Dead Loads
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5.3.2 Live Loads
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5.4 Section Properties
Depth of cross-section h = 393.6 mmWidth of cross-section b = 399 mmDepth between fillets d = 290.2 mmWeb thickness tw = 22.6 mmFlange thickness tf = 36.5 mmRadius of root fillet r = 15.2 mmCross-sectional area A = 366 cm2
Second moment of area (y-y) Iy = 99900 cm4
Second moment of area (z-z) Iz = 38700 cm4
Radius of gyration, (z-z) iz = 10.3 cm Warping constant Iw = 12.3 dm6
Torsion constant It = 1440 cm4
Elastic section modulus (y-y) Wel,y = 5070 cm3
Plastic section modulus (y-y) Wpl,y = 5810 cm3
Modulus of Elasticity E = 210000 N/mm2
5.5 Verification of load combination N1
N1: 43
IG+ 32
Qmax
Nsd=43∗0.5 ( per tower )∗1599+3
2∗0.5 ( per tower )∗30000∗1.15
= 26941 kN
A = 2 * 36600 = 73200 mm2
I = (A*d2) + Iz = (73200 * 2 * 11002) + (387*106) = 1.775 * 1011 mm4
i = √ IA tot
= 1101.2 mm
ʎ = Lk
i =
500001101.2 = 45.4
Lm
L0 =
2.02.2 = 0.91 (>0.9 and <1.7)
Therefore: ɗ = 1 + 50ʎ 2∗A tot
Atr . min
= 1 + 50
45.42∗4
1 = 1.097
Therefore, fictive slenderness: ʎ’ = ʎ * √ɗ = 45.4 * √1.097 = 47.556
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5.5.1 Verification of column member (troucou)
Condition: K1’ * Km * σ ≤ σe = f y
1.10 =
2751.10 = 250 N/mm2
Where:
σ = 26941∗103
4∗36600 = 184 N/mm2
σ k’ = π2 E
ʎ '2 = π 2∗21000047.5562 = 919.12 N/mm2
μ’ = σk 'σ
= 919.12
184 = 4.99
K1’ = μ'−1
μ '−1.3 =
4.99−14.99−1.3 = 1.08
i = 103 mm therefore ʎ = 2000103 = 19.42
Therefore Km = 1.035
K1’ * Km * σ = 1.08 * 1.035 * 184 = 205.93 N/mm2
205.93 < 250 N/mm2
OK
5.5.2 Verification of whole tower
ʎ’ = 47.556K’= 1.095
Condition: σ ≤ σe=σ y
k ' =
2751.10
∗1
1.095 = 228.31 N/mm2
σ = 204.92 < 228.31 N/mm2
OK
Cross section is adequate
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6 ESTIMATES CALCULATEDThe following cross sections of the main and the column beams for four different crane dimensions were tested using the same method and load as in sections 4 and 5.
Table 6: Cross sections calculated for 4 different models and CMS cross sections
CMS 1 2 3 4Load applied (t) 2000 6000 6000 6000 6000
Column height (m) 24.1 25 30 30 40Beam span (m) 27.5 30 40 40 50
Distance btw LP*(m) 12.7 20 24 24 32Steel grade of beam S355 S355 S355 S410 S355
Main Beam cross section (mm)
h: 3300b: 1150d: 2750tw: 25tf: 50
h: 4100b:1600d: 3390tw: 45tf: 75
h: 5350b:1900d: 5190tw: 60tf: 80
h: 5350b:1900d: 5080tw: 60tf: 80
h: 6500b:2000d: 5190tw: 70tf: 80
Self-weight (t) 61 98.38 193.3 188.2 300Lo (m) 2.2 2.2 2.2 2.5 2.2Lm (m) 2.0 2.0 2.0 2.3 2.0Lk (m) 48.2 50 60 60 80
Steel grade of column 275 275 275 355 275
Column Beam cross section
h: 288.54b: 264.5d: 193.67tw: 19.177tf: 31.75
r: not statedW10X112 (US specification)
h: 393.6b: 399.0d: 290.2tw: 22.6tf: 36.5r: 15.2UKC
356X406X287
h: 393.6b: 399.0d: 290.2tw: 22.6tf: 36.5r: 15.2UKC
356X406X287
h: 374.6b: 374.7d: 290.2tw: 16.5
tf: 27r: 15.2UKC
356X368X202
h: 419b: 407
d: 290.2tw: 30.6tf: 49.2r: 15.2 UKC
356X406X393*LP: loading pointsLo: distance between two column beamsLm: height of bracing unitLk: effective length of column
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Figure 15: beam cross section
7 GENERAL COMMENTS
7.1.1 Main Beam
Four different cranes are presented in section 6. Because the cross section needed are so large, they are not available commercially and so the dimensions used do not belong to a standard. As for the CMS main beam, the beam will have to be manufactured especially for the task.
The first design has similar dimensions to the CMS gantry crane but has a smaller span from the columns to the loading points. Despite the applied load having being tripled, the cross section of the main beam only increases by 80cm in height and 45cm in depth. This suggests that the position of the point load has a significant impact on the design and the span from the column to the load should be reduced as much as possible to reduce the cross section of the beam.
The second and third designs have exactly the same dimensions and loads but were calculated with a different steel grade to see the effect that this would have on the cross section of the main beam. Using S410 instead of S355 allows us to reduce the cross section needed for the beam, however this reduction is not outstanding. S410 is less common than S355 and would therefore be more expensive to procure, one must therefore look into whether the benefits of using this grade of steel are sufficient to outweigh the added cost.
The fourth case is an extreme case scenario, should the detector have an extremely large diameter. While one can still theoretically design a beam with a cross section large enough for this case the problem of its weight comes into play: can standard cranes lift it into position? Furthermore, is it possible to cast such a large beam?
7.1.2 Columns
The column cross sections needed are small enough that standard beams exist in such dimensions. For the purpose of this study UKB standards are used and the “Tata steel blue book” values and dimensions are used as reference.
As before, the first design is similar in dimensions to the CMS gantry crane. We can observe that the cross-section of the columns is noticeably increased in this case. The dimensions being very similar to those of the CMS crane, this is due to the increase it load.
The second design has the same cross section for the column as the first. The only difference between the two is the increase in height of the column; it must not have an enormous effect on the cross section needed.
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Table 7: Column dimensions
The third design has again been calculated with a higher steel grade to see its effect on the size of the cross section required. This, combined with a slight change in the column dimension allows us to noticeably reduce the cross section of the column needed. As S355 I not that uncommon and 16 of these beams will be needed, it may be interesting to consider this option for the columns.
Case four still uses standardised beams however Tata steel does not list many larger cross sections. Should the section requirements increase by much, one could use a higher grade of steel to reduce this requirement or would have to manufacture a beam specifically for the task. This would be very impractical as 16 of them would be needed.
7.1.3 Further design considerations
It seems that the cross sections of the beam and the columns will not be the limiting factor in this endeavour, however the design of the foundations need to be looked into as they will likely pose a greater issue.
Indeed, they cannot be too close to the shaft as they will interact with it, compromising the stability of both structures. However, having them further away from the shaft also implies a larger span for the beam and therefore an increased moment generated by the same load. This will result in a larger cross section being necessary for both the main beam and the towers.
The concrete plug on which the detector will rest is not assumed to be a limiting factor as high strength concrete is often used in high-rise buildings, capable of sustaining the large loads generated, and can be made to sustain up to 130N/mm2 (PCA, 2016). The issue may lie in the rails and the hydraulic pumps used to move the concrete back and forth.
Another aspect of the design of the beam cross section that will require looking into is the design of the stiffeners necessary in a class 3 cross-section.
One could also consider using higher grades of steel than the S355 used in the CMS gantry crane, as suggested by trial 3 above, as this reduces the dimensions of the cross section needed. These higher grades of steel are more expensive however, and a cost analysis way want to be conducted.
8 POSSIBLE CONTRACTORS
8.1 VSL
8.1.1 Company information
VSL designed and built the 2000 tonne capacity crane for the CMS. It has headquarters in St. Légier, Switzerland and provides technical consultancy and support from project planning to complete final design, construction engineering and on-site activities (Vsl-heavy-lifting.com, 2016).
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8.1.2 Contact information
VSL Headquarter
VSL International Ltd.
Saegestrasse 76 - CH-3098 Köniz - Switzerland
Phone: 41 58 456 30 00
Fax: 41 58 456 30 55
Email: [email protected]
8.1.3 Resources
VSL’s online catalogue provides information as to the capacity of the strand-jacks that they produce: these are of 10 to 580 tonnes with piston strokes between 160 and 550 mm (Vsl-heavy-lifting.com, 2016).
Table 8: VSL strand-jacker specifications (Vsl-heavy-lifting.com, 2016)
Maximum capacity strand-jacker on the VSL online catalogue is: 572.9 tonnes 4* 573 = 2292 tonnes (insufficient) 8* 573 = 4584 tonnes (insufficient)
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A higher capacity strand-jacker than the ones available on the online catalogue will have to be procured.
8.2 Dorman Long Technology (DL)
8.2.1 Company information
DL is specialised in the erecting of long span suspension and cable stayed bridges, and in engineering specialist modular construction operations such as heavy lifting, lowering and horizontal skidding operations (Dormanlongtechnology.com, 2016). With headquarters in Northamptonshire, UK, it provides consultancy services under an ISO 9001:2008 accredited quality management system and covered professional indemnity insurance (Dormanlongtechnology.com, 2016). Site support is also provided: site technicians are usually initially incorporated in a client’s team to provide assistance and official training of the client’s staff certifies them to competently operate the equipment (Dormanlongtechnology.com, 2016).
8.2.2 Contact information
For general enquiries please contact [email protected]
UKHead Office:The Charles Parker Building, Midland Road, Higham Ferrers, Northamptonshire, NN10 8DN, United KingdomTel. +44 (0)1933 319133Contact: Mr David Dyer. [email protected]
8.2.3 Resources
DLT designs and manufactures Strand-jacks with capacities from 15 to 1672 tonnes (Dormanlongtechnology.com, 2016)
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Figure 16: DL-S1672 type strand-jacker (Strand jack systems; Strand jacks, power packs and control systems, 2016)
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9 CONCLUSIONBased on the calculations undertaken in this study it seems that this project would be feasible.
The beam and the columns cross section are unlikely to be the limiting factor, however the column foundations need to be looked into as they will likely pose a greater issue.
The concrete plug is not assumed to be a limiting factor however the rails and the hydraulic pumps used to move the concrete back and forth may want to be looked into.
Another aspect of the design of the beam cross section that will require looking into is the design of the stiffeners necessary in a class 3 cross-section and the use of higher grades of steel.
As for what concerns the contractor who undertakes the endeavour: VSL is advantageous in that it is a locally based company that has worked on a similar project for CERN before and would undertake the design and construction of the crane. However it does not readily available strand-jackers of a large enough capacity. Such a strand-jackers would have to be ordered or constructed. DL does manufacture such strand jackers and would install them and train workers to use them.
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10 WORKS CITED
Desirelli, A. and Ferreira, L. (2006). CMS Lifting Gantry: Gantry Assessment
Dormanlongtechnology.com. (2016). DLT Strand Jacks 15 to 1672 tonnes capacity per jack. [online] Available at: http://dormanlongtechnology.com/en/Products/strand_jacks.htm [Accessed 15 Aug. 2016].
Dormanlongtechnology.com. (2016). Dorman Long Technology home page. [online] Available at: http://dormanlongtechnology.com/ [Accessed 15 Aug. 2016].
Vsl-heavy-lifting.com. (2016). Equipment | VSL | Heavy Lifting. [online] Available at: http://vsl-heavy-lifting.com/services/equipment.php [Accessed 15 Aug. 2016
Mentink, M. and ten Kate, H. (2016). Update on Detector magnets Design for FCC-hh.
Osborne, J. (2006). CMS Gantry for Detector Lowering.
PCA, A. (2016). High-Strength Concrete. [online] Cement.org. Available at: http://www.cement.org/cement-concrete-basics/products/high-strength-concrete [Accessed 23 Aug. 2016].
Strand jack systems; Strand jacks, power packs and control systems. (2016). 1st ed. [ebook] Available at: http://dormanlongtechnology.com/en/Products/strand_jacks.htm [Accessed 15 Aug. 2016].
VSL, (2006). Lifting Gantry Design Report. 296 2143 CERN CMS Lowering.
VSL, (2006). Method Statement for Dummy Load test
VSL, (2006). 2000t Lifting Gantry Designation of Main Parts. 296 2143 Cern CMS Lowering.
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