br tunnelling new eng

7/21/2019 BR Tunnelling New Eng

1/16

Tu

n

n

e

llin

g


2/16

Tunnel portalThe in i t ia l engineer ing works for theconstruction of a tunnel transform a mountains lope into a ver t ica l wal l , thereby forming

the tunnel porta l . These works are wideranging and may be subdiv ided betweenst ructura l works , consol idat ion works ,f in ish ing and protect ion works ; these s tagesemploy mater ia ls of d i f fe rent types andcharacter i s t i cs .

Reinforced soi lThese are st ructuresfor the containment,stabi l isat ion andrenatural isat ionof slopes andembankmentsat tunnel porta ls.

Soil nai l ingand surfacereinforcement

Tunnels excavated with traditional methods

The stabi l i ty of the slope iscontro l led dur ing construct ion ofthe porta l by means of sur facereinforcement consist ing main ly of

steel mesh and anchors (h ighstrength steel bars, se l f -dr i l l ingbolts, f ibre lass nai ls) , somet imescoated with shotcrete.

DrainageIn order to avoid instability problemscaused by inflowing water, drainagepipes made of synthet ic mater ia lsare used to col lect groundwaterf rom the deepest layers and carry i toutside.

Micro-pi lesMicro-pi les are f ixed into the

ground by dr i l l ing of holes.They form a vert ica l wal l f rom

which the excavat ion of thetunnel wi l l be star ted.

Fibreglass reinforcementfor foundation pilesI f foundat ion p i les are used insteadof micropi les, the t radit ional steelconcrete re inforcement is replaced byf iberg lass e lements which garanteethe same mechanical st rength,enabl ing fast progress in theexcavat ion of the heading face.

Rockfal l barriers

The protect ion works against fa l l ingrocks represent a fundamentalaspect in the design of tunnel portalworks, having a d irect ef fect on thesafety of the overal l works.


3/16


4/16


5/16


6/16

6

DrainageThe durabi l i ty of the f ina l l in ing dependson the dra inage works which enable anywater tab les to be co l lected and dra inedthrough channels and p ipes . Th is avo idsinf i l t rat ion of water in to the concrete and,therefore, l imits problems l inked to freezingand thawing cyc les .

Drainage

Drainage p ipes are used,somet imes in combinat ion with

f lat dra inage composites, in orderto quickly lower the groundwater

level in the deep rock masses.

Geotexti les

The MacTex f ami l y o fgeotext i les represents anexcel lent so lut ion to

protect the waterproofingof the tunnel formed byHDPE or PVC sheet ing.

Drainage geocomposites

The MacDrain drainage geocompositesreduces pore water pressures andthereby reduce the threat of saturatedground condit ions.


7/16


8/168

First l iningThe f i r s t l in ing i s appl ied immediate ly a f ter excavat ion of the heading face. Th istemporary support l in ing i s commonly made of s tee l f ib re re in forced shotcrete . I fs t ructura l l y requi red, th is phase a lso compr ises the insta l la t ion of re in forcemente lements cons is t ing of s tee l sect ions that are deformed to the contour of thetunnel . For example s tee l r ibs or la t t i ce g i rders that are longi tud ina l ly connected

together to form the support re in forcement . These are qu ick ly incorporated intothe sprayed s tee l f ib re re in forced concrete to form a tough st ructure enabl ingabsorption of the f irst deformation forces of the tunnel. Where necessary, additionalrad ia l re in forcement in the form of var ious types of s tee l anchors i s insta l led.

Self-dri l l ing boltsand steel anchors

These solut ions are used to contro land/or reduce convergence

of the excavated tunnel sect ion.

The re inforcement range compr isessteel anchors, se l f -dr i l l ing rock

bolts and h igh-st rength steel bars

Plastic ising and acceleratingadmixtures

The superplasticisers maintain the workabilityof shotcrete, preserving the qual i ty andcharacter istics dur ing t ransport and pumping.Rocks i l (s i l icates) and Apral (a lkal i f ree)admixtures accelerate the set t ing t ime byreducing the consistency dur ing spraying andhence, improving gr ip to the substrate orprevious layers.

Wirandsteel f ibresWirand steel f ibres g ive a combined compressive and bendingstrength to the shotcrete l in ing, increasing substant ia l ly thetoughness of shotcrete, improving the reinforcement performanceand increasing the work safety. Specia l ised Maccafer r i dosageequipment is provided to add the exact ing quant ity of steelf ibres dur ing the batching operat ion in the mixing p lant .

Steel arches

These consist of pre-shaped steel sect ions,to provide f i rst stage support . Var iat ionshave a lso been implemented in order toimprove the insta l lat ion, with the use ofparts of the arches that are extendable PMET,thereby making the insta l led r ib imm ediatelyact ive. Text i le sacks, known as B IM BAGS,are a lso p laced behind the arches and whenthey are inf lated, using the same mortar asthe shotcrete, they f i l l per fect ly the spacesbehind the arches.


9/16


10/1610

Consolidation of excavation faceThe adopt ion of th is method is increas ing wor ldwideand is used main ly to re in force and consol idate theso i l mass in f ront of the excavat ion face, therebyenabl ing fast progress wi th la rge-s ized excavat ions .I t tends to be used in par t icu lar geolog ica l condi t ions

and in so i l s cons idered to be d i f f i cu l t to excavate . Themethod cons is ts in re in forc ing the excavat ion face by

insta l l ing f ibreg lass e lements in sub-hor izonta l ho les ,which are then grouted to form a set of micro-piles aroundthe ent i re sect ion. Th is conta ins the s t resses induced bythe excavat ion and s tab i l i ses any thrusts . Approachessuch as ADECORS (Analys is of Contro l led Deformat ion

in Rocks and Soi l s ) are used to prepare the f ina l des ignsfor such techniques.

Drainage

Drainage pipes are used in orderto quickly lower thegroundwater level in the deeprock masses.

Special expansive mortars

These are dry ready-mixed products thatare added to water and injected in holesat the excavat ion face. Due to their

expansive character ist ics they compressthe soi l around the dr i l led hole, therebyguaranteeing a better adherencebetween the re inforcement e lement andthe soi l i t se l f .

Polyurethane resin

These are chemical products thatare mixed before the grout ingstage to create a l ightweight andexpansive closed cel l foam. Whenit comes into contact with wateri t forms a foam that b locks anyaccidental in f low of water. I t isa lso widely used to f i l l thecavit ies that somet imes form orwhich are encountered dur ingtunnel excavat ion work.

Fibreglass reinforcement elements

These are ext ruded elements formed by g lass f i laments andpolyester resin that are manufactured with var ious cross-sect ions, f rom hol low to sol id ; the lat ter having a h ighmechanical st rength, which may be compared with steel ,whi lst maintain ing i ts l ightness and versat i l i ty. Requiredcharacter ist ics to make the excavat ion.


11/1611

A3 MotorwaySalerno-Reggio CalabriaModernisation and upgrading of

the section between Salerno and

Reggio Calabria ( Italy)

Projects and works

A1 MotorwayMilan-NaplesNew Variante di Valico motorway

section. Upgrading of the

Apennine section between

Bologna and Florence (Italy)

High-Speed Railway LineMilan-NaplesConstruction of the section between

Bologna and Florence (Italy)


12/1612

Tunne ls excavated with TBM

Access shafts -

StationsTBM driven tunnels often require the construction ofaccess shafts or trenches through whic the TBM islowered down to the level at which the excavation starts.The shafts are formed by constructing reinforced concretewalls down to the ground level, sometimes toconsiderable depths and with large dimensions.Water tables may be encountered during the constructionof these shafts or trenches.The appropriate means to keep the work environmentdry are consolidation and waterproofing grouting. Thevarious work stages include: steel or fibreglass

reinforcement of the concrete, pipes fitted with valvesfor consolidation grouting, chemical consolidation mixes.

Chemical

Consolidation MixesGroutmasterThese are ready made products wi thGroutmaster granules that conta in boththe act ive par t and i ts reagents . S imply byadding water and mix ing, i t t ransforms intoa low v iscos i ty so lut ion, that enables i t topermeate into so i l s even with a lowpermeabil ity. Soils grouted with this chemicalmix acqui re impermeabi l i ty character i s t i csand the compress ive s t rength of the so i l s

are increased.


13/1613

Precast

segmentsThe f ina l l in ing cons is ts ofprecast concrete segments .These segments can bereinforced solely with Wirand

stee l f ib res or in combinat ionwith convent ional s tee lre in forcement . In order toreduce concrete spa l l ingFibromac polypropylene f ibrescan be added to ach ieve anef f i c ient pass ive f i reprotect ion.

BarcelonaLine 9

Line 9 is 43 km long and runs fromthe El Prat airport in two differentd i rect ions , wi th 43 s tat ions .The f ina l l in ing for the tunnel i smade of precast concrete , wi th acombinat ion of convent ional s tee lre in forcement and Wirand s tee l

f ib res (FF1 and FF3) .

The tota l product ion quant i tyamounts to 450,000 m 3o f f ib rere inforced concrete .Maccafer r i dos ing systems havebeen espec ia l l y des igned andinsta l led in order to ensure prec isef ibre quant i t ies and quick batch ing.


14/1614

Research and DevelopmentThe ent i re range of products compl ieswith the h ighest s tandards of qual i ty atboth a nat ional and internat ional leve land they constantly undergo tests to provethe i r per formance. A l l new products are

patented in the main countr ies .Our technical staff has prepared numeroustechnica l papers over the years and isof ten ca l led upon to jo in wi th group s ofexperts for pro jects and technica lcommit tees .

Maccafer r i and E las promote and car ry outcont inuous research with in the tunnel l ingsector in co l laborat ion with un ivers i t ies ,government bodies and research inst i tutes .Th is apt i tude for technica l innovat ion i s the

resu l t o f cont inuous dedicat ion, which,a longs ide exper ience and technica l know-how, has enabled us to reach h igh l eve ls ofef f i c iency . Concepts are deve lopped intoversat i le so lut ions to meet market spec i f i crequi rements .

Fibres as onlyreinforcementComputational analysis and laboratory

tests for the characterisation of theflexural performance of the fibre reinforcedconcrete to prove actual material.

Fire resistancetests

Pla in concrete

PP f ibre

reinforced

concrete

Reduced

spal l ing

depth

CE MarkingSince 2008 Wirand products havethe EC-Declarat ion of Conformity,issued by a not i f ied body:

- Cha rac te r i s t i c s o f f ib r es- E f f ec t o f f ib res on Re fe rence

Concrete- In spec t ion o f f a c to r y and

cont inuous survei l lance.

Panel tests

Test ing of hardened shotcrete:

- Mater ia l s propert ies- Cross sect ional propert ies- St ructural propert ies


15/1615

Technical SupportWe recognize the importance of wor ld-c lasstechnical support. Our goal is that every supportinteract ion s t rengthens our c l ients overa l lsatisfaction and reinforces our relationship withthem. We are ab le to prov ide a fu l l tec hnica l

serv ice to our customers . Not mere ly a s implecollaboration but a true partnership from design

stage over job s tar t unt i l the end of the pro ject ,prov id ing consu l tanc ies , t ra in ing, and a l lowingal l our customers to benef i t f rom our wor ldwideexper ience.Our technica l serv ice prov ides :

- Product se lect ion accord ing with the spec i f i crequi rements

- Pro ject consu l tancy and analys is- On s i t e t e s t s and a s s i s t ance- Research and deve lopment wi th un ivers i t ies

and research inst i tutes- Wor ldwide presence with more than 40

operat ing companies- F ibre dosage equipments .

Big bags batching systems Carton boxesbatching system


16/16

Founded in 1879, Off ic ine Maccafer r i wassoon to become a reference wor ldwide in

the design and development of advancedsolut ions for erosion contro l andreinforcement st ructures. Over t ime,however , the company has innovated andevolved so that today i t is a lso a re l iab lepartner for complex civ i l and

environmental engineer ing appl icat ions,with specif ic focus on the underground

works.Maccafer r i s presence throughout thewor ld a l lows the company to deal withproblems which results in new know-howthat, in turn, feeds into further innovationfor other so lut ions of fered on the market .

As wel l as the parent company in I ta lyand subsidiaries in France, Britain, Russia,

Spain and Portugal, the company is a lsoact ive in a l l f ive cont inents, with 46operat ing companies such as Lat inAmer ica, New Zealand, USA. Where thereis no internal sa les force, there aredist r ibutors in a l l the cont inents.

E las, for more than ten years now, has

been supplying the construct ion marketwith exclusive, h ighly innovat ive anddist inct ive products for undergroundbui ld ing projects, which are customisedand appl ied in accordance with thespecif ic technical requirements. Ourski l led, exper ienced team provides the

customer with specia l ist technical

consultancy, ranging f rom an analysis ofthe project , the ident i f icat ion of theproduct and their insta l lat ion, payingpart icu lar at tent ion to the specif icappl icat ion processes.Research and development occupancy aposit ion of pr imary importance, with a

view to ensur ing the cont inuous

improvement and development of theproducts and their per formance features.These operat ions take p lace on si te andby means of universi ty laborator ies, andare ta i lor-made to guarantee maximumoperat ing ef f ic iency and completecustomer sat isfact ion.

Officine Maccaferri S.p.A.Via Agresti, 6 - P.O. Box 39640123 Bologna - ItaliaTel. +39 051 6436000Fax +39 051 236507e-mail: [email protected]

www.maccaferri.com

ELAS Geotecnica srlCentro Comm. lotto 3/2120090 S. Felice - Segrate (Mi) - ItaliaTel. +39 02 7533252Fax +39 02 [email protected]

www.elasgeotecnica.it

2 0 0 9 O f f i c i n e Ma cca f e r r i S . p . A . - B o l o g n a - I t a l y - P r i n t : L i t o g r a f i a Z u cch i n i - P r o j e c t : g r a f i cam o n t i . co m - P h o t o : O f f i c i n e Ma cc a f e r r i a r ch i v e s

br tunnelling new eng

Documents