1、 - STD.BSI BS EN 77b-2-ENGL 1997 Lb24bb Obb3574 LbT - BRITISH STANDARD Underground tanks of glass-reinforced plas tics Horizontal cylindrical tanks for the non-pressure storage of liquid petroleum based fuels (GRP) - Part 2. Wansport, handling, storage and installation of single wall tanks m BS EN 9
2、76-2 : 1997 * * v, The European Standard EN 9762 : 1997 has the status of a British Standard ICs 23.020.10 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW STD-BSI BS EN 77b-2-ENGL 1997 Lb24bb9 Obb3575 OTb direction of the Sector Board for Materiais and Chemicals, was published
3、 under the authority of the Standards Board and comes into effect on 15 December 1997 Amd NO. (0 BSI 1997 BS EN 9762 : 1997 D - present to the responsible European committee any enquiries on the interpretation, or proposals for change, and keep the TJK interests informed; - monitor related internati
4、onal and European developments and promulgate them in the UK. A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in
5、the BSI standasds Catalogue under the section entitled International Standards Correspondence Index, or by ushg the Find facility of the BSI Standards Electronic Catalogue. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document co
6、mprises a front cover, an inside front cover, the EN title page, pages 2 to 16, an inside back cover and a back cover. ISBN O 580 28930 3 I I STD.BSI BS EN 97b-2-ENGL L777 = lb24bb7 Obb357b T32 EUROPEAN mmDARD EN 97 deadmen Concrete beams laid parallel to the tank axis which prEN 9761 Underground ta
7、nks of glass-reinfmed plastics (GRP) - Horizontal tindrcd liquid petroleum based fuels - Part 1: Requirements and test methods for singk waU tanks allow the soil weight above the beams to be utilized in tank anchoring (SW figure 3.4). Position on the tank used for lifting purposes. 3.17 water table
8、tanksfor mmmm stove of 3.16 lifting position 3 Definitions For the purposes of this standard the following definitions apply: 3.1 cylinder Part of the tank that forms the cylindrical portion of the body 3.2 end Curved portions of the tank located at the ends of the cylindrical portion. Permanent, sh
9、ort term tidal or frequently changing water level below ground level at the tank location which marks the upper level of the zone of groundwater saturation. 3.18 high water table Site with a water table having the depth below ground to the average seasonal water level of between O and 4 m. 3.19 tank
10、 pank compiymg with EN 9761. 3.20 visual inspection 3.3 cylinder reinforcing ribs Circumferential extemai ribs fully bonded to the cylinder or intgraly formed with it. 3.4 compartment an excavation. Examination of the tank by the unaided eye. 3.21 sheet pile Timber or steel sheeting used to support
11、the sides of Portion of the tank created by an internal partition. 3.6 manway Hole in the uppermost portion of the cylinder or tank ailowing access. 4 naIlsport The tank shall be placed on the transporter ensuring that it is not placed on any sharp protnisions that will cause damage. Suitable cradle
12、s or checks shail be 3.6 manway lid Plate bolted to the manww. used The tank shail be secured on the vehicle by means of GRP, nylon or similas non-metaic straps. 3.7 access chamber Chamber to provide access to the manway lid. The straps shall only be tightened sufficiently so as to prevent tank move
13、ment. Care shail be taken not to overtighten the straps and cause damage of the tank. O BSI 1997 STDn8SI BS EN 77b-2-ENGL 1797 ZbZqbb9 Obb3579 7LI.l Page 4 EN 97 b) filling the tank with water and applying air pressure at 10 kPa for 60 min, c) air pressure at 35 kPa for a minimum of 60 min The press
14、ure reading shall be taken from a gauge sited on the tank top. The gauge shall be of such a size that losses of pressure can be readily indicated. A pressure relief valve set to 40 kPa shall be provided. NOTE. It is recommended that a calibrated gauge with a 150 mm dial size and a maximum pressure r
15、eading of 50 Wa is used. Aiternativeiy a water manometer may be used with a diameter of 10 mm and graduations marked in centimetres. 8.17 Dimensional tests Remeasure the tanks vertid diameter when the tank is backfilled to grade to ensure that it has not changed by + 2,O % or - 1,0 % variation outsi
16、de this figure indicates incorrect backfilling. Horizontal deflection may also be measured. 8.18 Completion of installation When the testing has been satisfactorily concluded fit the access chamber, if used (see annex A, clause A.4) to the tank and commence the connection of anciliary piping. Test t
17、he piping in the normal way and continue bacldilling to provide a minimum thickness of backfill material of 500 mm above the tank body. If the pipework pressure exceeds 35 kPa then the pipework shall be isolated from the tank. 8.19 Completion of top cover and surfaces nks subject to traffic load sha
18、ll have a minimum cover of 850 mm backfill plus 150 mm of asphalt or paving slabs laid on 50 mm of sand, or 500 mm backil and 150 mm reinforced concrete slab. Asphait and concrete slabs shaU extend a minimum 300 mm beyond the tank in ali directions. nks not subject to a traffc load require a minimum
19、 of 500 mm of backfill. O BSI 1997 Page 9 EN 976-2 : 1997 Annex A (normative) Installation components requirements A.4 Access chamber Any access chamber, if provided, shaii exclude ground water, retain fuel spdlage and allow free access to the A.l Backnll material The material shall be clean and gra
20、ded and freeflowing, -ee from ice, snow, clay, organic materials and completely free from oversize heavy objects that may damage the tank if dropped from a loading skip. The minimum bulk density shall Gravel The backfill material shail not have more than 3 % passing a 2,4 mm screen. The material sha
21、il be well-rounded pea gravel with a mix of particle size not less than 3 mm and not more than 20 mm. Stone crushings Stone crushings with ele size of not less than 3 mm nor more than 16 mm, of which not more than 3% shall pass a2,4mm screen. Sand Sand shall be well graded and shall have less than 8
22、 % passing a 75 pn screen with the largest particle size lessthan3mm. Sand/gravel mixtures Mixtum of sand and gravel may be used provided that the constituent parts comply with those for gravel, stone cnishings and sand described above. Sand gravel mixtures shall be compacted in accordance with the
23、detaiis given in ciause B.3. A.2 Anchorage points Anchorage points shall be constructed from 20 mm diameter steel bars bent to shape and located with the feet under the base reinforcement. They shall not be located underneath the edge of the tank nor within 150 mm of the edge of the base. All expose
24、d metal parts shall be hot dip gahnized and site coated or protected agauist corrosion by an aiternative appropriate method. Alternatively, the anchor stsaps can be taken under or through the base, emerging on the top face at the anchor point positiow, in such cases the stsaps shall be vertical. be
25、1 500 -3. A.3 Anchor straps Anchor straps shall be manufactured from GRP, nylon or similar non-metallic materiai offering resistance to the environment and adequate restraint to resist the buoyancy which would be generated by an empty tank fuJly surrounded by backfill. The straps are to be located i
26、n the positions shown on the tank by the manufacturer. -. manway lid. It shall not transfer tsaffic loads from the surface to the tank. The cover from the access chamber shall be supported from the traffic slab and seaied to prevent the ingress of surface water into the chamber. Annex B (informative
27、) Installation recommendations B.l Concrete base-construction Where a base is required, it should consist of a minimum of 200 mm reinforced concrete comprising two iayers of light reinforced mesh (200 X 200 pitch, 7 mm diameter wires, 3,022 W2), of a minimum strength of 21 Nhnm2 after 28 days, to be
28、 laid level on 50 mm sand blinding. Where ground conditions require, sulfae resistjng concrete should be used The base slab should extend a minimum of 300 mm beyond the sides of the tank and should at least be equal to the overall length of the tank B.2 Installation procedure for pea shingle or crus
29、hed stone backlls (gravel) Bed Provide a minimum of 200 mm of gravel backfill bedding over excavation bottom or concrete slab. Place tanks on bed and anchor. Bacwlling Use same materiais as bedding. Place first 300 mm lift evenly around tanks. BacHi must be pushed completely beneath tank bottom betw
30、een ribs and under end caps to provide necessary suppoxt A long handled probe can be used to penetrate backfill and push it between all ribs and at 3 to 5 points under end caps. Place another 300 mm lift of backfill evenly around tanks. Repeat the probing of backfill. After completion of second lift
31、, backfill can be brought to top of tanks or grade without additional handwork (Compaction may be required for slab support). Note that in tight areas in straight-walled excavations, it wiU be dicult to properly probe the gravel without entering the excavation. Use of a special curved probe may be n
32、ecessary The following procedure is the most effective for the curved probe. a) After setting the tank on the gravel bed, probe the entire tank bottom and around the end caps. b) Place the first 300 mm lift of backfill. c) Probe the entire tank bottom and end caps again. d) Place the second 300 mm l
33、ift of backfill. e) Switch to straight probe section and probe tank again- O MI 1997 STD-BSI BS EN 97b-2-ENGL 1777 lb24bb9 0bb3585 T45 Page 10 EN 976-2 : 1997 Concrete C 25 1 Mesh layers Deformed bars KS 40 2 3 Lug, diameter 20 nun, hot dip galvanized and site coated Deformed bars, 12 mm diameter, 1
34、50 mm spacing both ways Figure 3.1 Concrete base 1 Long-handed probe 1 Long-handledprobe 1 Long-handled probe 1 Long-handed probe 2 Frst300mmiiftofbackfU 2 First3mmiftof 2 Second 300 mm lift of 2 Curved probed section 3 200mmbed 3 200mmbed 3 200mmbed Figure B.2 Installation procedure using gravel ba
35、ckfill backii backfill 1 Slope determined by soil stability 2 Compactedbeding 1 RIGHTTanknnnly supported 2 WRONGPoortank 3 Board to push backfill 4 Firstiiftofbackil 5 Bed 6 Backtill support 1 Useboardtomanually compact sand under end 1 Mechanically compacted sandinifts Figure B.3 Installation proce
36、dures using mechanically compacted sand backfill O BSI 1997 STD.BSI BS EN 77b-2-ENGL 1777 LbZLibb7 Obb358b 781 9 Page 11 EN 9762 : 1997 B.3 Installation procedures using mechanically compacted sand backfiIl NOTE 1. The mechanically compacted sand procedure requires the tank installers to enter the t
37、ank excavation to compact the sand. Appropriate safety procedures should be taken (shore or cut back the excavation wails) whenever entering tank excavation to protect against collapsing excavation wails. NOTE 2. Because of the need to achieve high levels of compaction, extreme care should be taken
38、to monitor the installation to confirm and measure proper compaction. Bed Provide a minimum 300 mm level backfd bed over the excavation bottom or concrete slab. The bedding should be smooth and level. Compact the sand bed for the entire length and width of the tank. Place the tanks in the excavation
39、 on the compacted backfd bed. Bml Uing Use the same materiais as the bed- for the backfill Place the first 300 mm lift evenly around the tanks. Hand shovel the sand between the ribs and under the end caps. Use a 50 mm 100 nun board to push and compact the sand under the tank between the ribs and und
40、er the end caps. It is very important to ensure good manuai compaction under the end cap and tank bottom. Considerable manual effort is required to achieve good placement and compaction. The first two lifts wiil require this manual probing and compaction. After compacthg the first 300 mm iayer, more
41、 sand can be added in 300 nun iifs. At each 300 mm iayer of sand, the sand should be well tamped with a mechanical piate vibrator (operation at 2 O00 to 3 O00 vibrations per min). Ideai sand compaction normaiiy occurs when the moisture ranges from 10 % to 18 % by mass. Compact to a minimum of 95 % s
42、tandard Proctor densiW. Bacllling over tanh Place sand backW over the tank top. It is recommended that the sand bctckfd be compacted in 300mm lifts to a minimum of 95% standard Proctor density to provide support for the trafc pad and for the product lines in the tank area B.4 Classification of groun
43、d conditions See table B.l. B.6 Sleepers - Construction See figure B.4. B.6 Concrete bases for tank anchoring See figure B.5. * * m O BSI 1997 Page 12 EN 9762 : 1M Instaiiation categories NATIVE SOIL Table B.l Classincation of ground and installation conditions I I II III IV V Soil description* Mini
44、mum cohesion (“a) Minimum bearing capacity (Wa) Minimum soil modulus pa) Minimum SFT blow counts* verygood good fair poor very poor 36 18 12 6 6 168 45 24 12 12 278 1,7 174 017 0,7 18 12 5 2 c2 CLASS 1 TANK EXCAVATION pit walls vewstable stable unstable unstable unstable Minimum tank to tank (m) Min
45、imum tank to pit wall (mm) Geotextile required 450 450 450 450 450 450 450 0,5D 0,5D 450 no no no Y= Y= Permanent sheet piles required CLASS 2 TANK EXCAVATION * More detaed soil descriplioc Very good: Good: Fi3k Poor: Very poor: very stiff days, dense sands, rock stiff clays and medium to dense sand
46、s; soft to medium clays or loose granular soils, very soft to soft clays and very loose to loose sands; weaker than IV, typicaiiy very fluid. * SFT standard penetration test. no no no no YB O BSI 1997 pit walls Minimum tank to tank (mm) Minimum tank to pit wall (m) verystable stable unstable unstabl
47、e unstable 450 450 450 450 450 450 0,5D 0,5D 0,5D 450 Geotexte required Permanent sheet piles required no no no Yes Y= no no no no Yes * m * STD.BSI BS EN 776-2-ENGL 1997 W lb2qbb9 Obb3588 754 9 Page 13 EN 9762 : 1997 Aitemative 1- Diameter 1600 n w 5 1 Lug, diameter 12, hot dip galvanized and site
48、coated 2 Deformed bars, diameter 10, 4 pieces 5 Sie 3 Round steel, diameter 6, centre to centre spacing 100 6 Double Aitemative 2 Diameter 2000 4 Deformed bars, diameter 10, 8 pieces -r- 2% 3 i 5 6 1 Lug, diameter 16, hot dip galvanized and site coated 2 Deformed bars, diameter 12, 4 pieces 5 Single
49、 3 Round steel, diameter 8, centre to centre spacinp 125 6 Double Aitemative 3 Diameter 2000 4 Deformed bars, diameter 12, 8 pieces n 1 Lug, diameter 20, hot dip galvanized and site coated 2 Deformed bars, diameter 16,8 pieces 5 Single 3 bund steel, diameter 8, centre to centre spacing 150 6 Double Concrete C 26 Concrete cover 30 nun Round steel St 37 Deformed bars KS 40 Dimensions in mm 4 Deformed bars, diameter 16, 8 pieces Figure B.4 Sleepers O BSI 1997 STD-BSI BS EN 97b-2-ENGL 1997 1b24bb7 bb3589 b90 D Page 14 EN 97
