Design and Construction of the Bridges on Guangzhou Metro Line 4

Transcription

1 Avalable onlne at Proceda Engneerng 14 (2011) The Twelfth East Asa-Pacfc Conference on Structural Engneerng and Constructon Desgn and Constructon of the Brdges on Guangzhou Metro Lne 4 X.H. HE 1ab, X.L. MENG 2 and L. J. LI 2 1 School of Cvl Engneerng & Archtecture, Central South Unversty, Chna 2 GuangZhou Metro Corporaton, Chna Abstract Elevated ral transt has been developed n some bg ctes n Chna n recent years. However, specalzed codes for desgn of the brdges n the elevated ral transt system have not yet been establshed. Based on the prestressed concrete (PC) box grder brdges on Guangzhou metro lne 4, some techncal features of desgn prncple and technology requston, ensemble plan and desgn load of brdges on urban ral transt are explored. At the same tme, due to the frst tme used on a large scale n manland of Chna, the short-lne match method technology and the prncples of the coordnate transformaton are brefly ntroduced, and the formulas of spatal dmensonal coordnate transformaton for geometrc shape control and calculatng the translaton amounts of precastng by the short-lne method are deduced. In addton, some of the methods for the geometrc shape control of the precastng by the shortlne method and cantlever assembly of the segments are also brefly dscussed. Keywords: elevated ral transt, brdge, desgn prncple, short-lne match method, geometrc shape control a Correspondng author: Emal: xuhuhe@mal.csu.edu.cn b Presenter: Emal: xuhuhe@mal.csu.edu.cn Publshed by Elsever Ltd. do: /.proeng Open access under CC BY-NC-ND lcense.

2 X.H. HE et al. / Proceda Engneerng 14 (2011) INTRODUCTION Wth the development of economc and socety, the constructon of fast ral transt systems s becomng a trend for development and modernzaton of cty nfrastructure. Due to superor effcency, envronment-frendly and aesthetc value, urban elevated ral transt has been developed and appled n some bg ctes n Chna. Guangzhou s one of the mportant ctes of developng urban ral transportaton, before the 16 th Guangzhou Asan games 2010, the total length of metro lnes s up to 255 km. Guangzhou metro lne 4 s one of the man metro lnes from north to south wth a total length of 56 km ncludes vaduct brdges of almost 30 km from Xnzao to Nansha. The Xnzao to Huangge secton began operatons on Nov , and Huangge to Nansha secton opened to traffc on May 1 st The brdges on Guangzhou metro lne 4 are all prestressed concrete (PC) box grder brdges, and man brdge types nclude smply supported brdges, contnuous beam brdges and a large span contnuous-rgd frame brdge. Guangzhou metro lne 4 s the frst tme to use short-lne match method on a large scale. The constructon plannng map and typcal brdges of Guangzhou metro lne 4 are shown n Fgure 1. (a) Fgure.1 Guangzhou metro lne 4: (a) plannng map; (b) typcal brdge (b) Based on the Guangzhou metro lne 4 vaduct brdges, ths paper frst nvestgates the desgn the technology problem of desgn prncple and technology requston, ensemble plan and desgn load of brdges on urban ral transt. Then a three dmensonal (3D) coordnate transformaton formula of geometrc control for short-lne match method s deduced n ths paper, and some methods and measures for geometrc control of the precastng by segment short-lne match method and cantlever assembly of the segments are also brefly dscussed. 2. Desgn descrpton 2.1. Desgn prncple and technology requston As an mportant urban landscape, the prncple of beauty, economy, advancement and practcalty s requred. In order to satsfy the scale harmony needs, the brdge heght to span rato s 1/2.3, the box grder heght to brdge heght rato s 1/4 to 1/5, the per wdth to grder heght rato s 1/1.6. On the bass of sght beauty, the desgn must satsfy the operaton functon of safety, durablty, economy. At the same tme, the structure desgn should am at standardzaton and seres for easy constructon.

3 128 X.H. HE et al. / Proceda Engneerng 14 (2011) Due to specalzed codes for desgn of ths type of vehcle loadng n the urban ral transmt system have not yet been establshed, brdge desgn thus usually refer the relatve natonal ralway desgn codes. The vertcal deformaton allowable value s L/2000 for span less than 30 m, and L/1500 for span larger than 30 m. The frst lateral natural frequency should not less than 90/L Span arrangement and cross-secton layout The PC box grder structures of Guangzhou metro lne 4 are amed at the concse and unfed appearance, convenence for factoral producton and standardzed constructon. Consequently, 30 m span smply supported box grder brdges s selected as a standard span n general dstrcts, 20m, 25m, 27.5m, 32.5, 40m and 41.9 m as the adustment spans. Whle for the crossng over rver and ntersecton nodes, the contnuous beam or contnuous-rgd frame brdges are used n order to reduce ts nterference wth the on-ste ground and shp transportaton and nearby resdents. The largest brdge s m Shawan contnuous rgd frame brdge, the Shqaol brdge s the largest contnuous brdge consstng of two centre spans of 80 m and two sde spans of 52.5 m each. Accordng to the ral network plannng and vehcle gauge, the cross-secton layout of brdges s dentfed as: 0.2m (ant-collson wall) +8.9 m (two tracks and a passenger evacuaton platform) +0.2 m (ant-collson wall) (Xong 2005). The cross-secton layout of 30m smply supported brdge s shown n Fgure 2. For the segment precast brdge, the standard segment length s 2.5 m for smply supported brdge based on the capablty of constructon, lft and transportaton. Fgure.2 Typcal cross-secton 2.3. LIM load The Guangzhou metro lne 4 s the frst metro lne to use the lnear nducton motor (LIM) metro system n Chna. The LIM metro system s a new urban transportaton system ncorporatng element of maglev and tradtonal ral transportaton (Hrosh 1999).The total length of the tran s 71 m wth four vehcles. The wdth of the vehcle body s 2.8 m. The average axle weght s 101 kn (desgn value s 120 kn). The maxmum desgn velocty of the LIM tran s 90 km/h (Pang and Gao 2006).

4 X.H. HE et al. / Proceda Engneerng 14 (2011) Short-lne match method In terms of the ste condtons and comparson results, except for cast-n-place usng balance cantlever method and ntegral framework, the man constructon methods n Guangzhou metro lne 4 are short-lne match precastng method and full-span precastng method. The lne on north of Shawan rver va hllock and countrysde, the full-span precastng and erecton method was adopted. However, n the south of Shawan rve, the metro lne bult on the man load of Shnanlu, the short-lne match precastng method was adopted. Due to the short-lne method s more complcated than long-lne method and other constructon methods, and t s the frst tme to use on a large scale n manland of Chna, the emphass of ths paper s to nvestgate the key technology of short-lne method Coordnate transformaton prncples Short-lne match method s an effectve approach to precast brdge n a lmted feld. The method dvdes a grder nto several segments and only one mouldng board s requred to precast. The precastng geometrc shape control of short-lne method s performed by adustng the spatal poston of matchng segment relatve to castng segment (local coordnate) to ensure the brdge desgn shape (global coordnate). Therefore, the coordnate transformaton between global and local coordnates s requred for the precastng geometrc shape control of short-lne method. The man procedures are: (1) confrmng the global coordnates system n terms of desgn shape and the control ponts global coordnates of each ont; (2) calculatng the drecton cosnes of every local coordnate and ther translaton relatve to global coordnates; (3) translatng the global coordnates of each control pont to correspondng local coordnates; and (4) calculatng the translaton of each segment from castng poston to matchng poston. It s noted that the frst segment no matchng segment, but only float end mouldng board, and the translaton calculaton of the last segment s not necessary Formulas for transformaton of the spatal coordnate As shown n Fgure 3, t s assumed that there are three control ponts on each ont of brdge segments, L means left control pont, M means mddle pont and R means rght control pont. L and R control the segment elevaton, and M controls the plane shape. In global coordnate ( X, Y, Z) system, Z s assumed as vertcal drecton, X s grder axs drecton, and Y s lateral drecton. The th ont control ponts are M, L and L, respectvely, whose coordnate components n global coordnate system are XM, YM, ZM, XL, YL, ZL, XR, YR, and ZR, respectvely. The vector T M, L, R, f M T XM, YM, ZM, L T XL, YL, ZL, R T XR, YR, ZR. For the segment need castng, the ont between fxed end mouldng board and the fnshed segment s looked as the fore ont, so a local coordnate system can be confrmed. In the local coordnate system, the orgn of coordnates s the M pont of the fore ont, X axs s defned by the two adacent M ponts, Y axs s defned from M pont to L pont of fore ont, and Z axs can be confrmed by X and Y. As shown n Fgure 4, the rear ont of the th segment s numbered 0 or -1, the number of the th segment fore ont s same to the segment number, there are one fore ont and one rear ont fore each segment, the fore ont of the th segment s same to the rear ont of the 1th segment. Whle a segment s located n the castng poston, the fore ont s thus located on the fxed mouldng board.

5 130 X.H. HE et al. / Proceda Engneerng 14 (2011) L M R N-1 N N-1 N Fgure.3 Jont control ponts Fgure.4 Segment and ont number In the global coordnate system, the coordnate vectors of u, v and w axs n the local coordnate system of the th ont are u M 1 M, v L M w u v, respectvely. The angles between u and X, Y, Z axes of global system are 1, 1, 1, the angles between v and X, Y, Z axes of global system are 2, 2, 2, the angles between w and X, Y, Z axes of global system are 3, 3, 3, respectvely. Then the drecton cosnes of three axes of local coordnate system are: 1, cos 1, cos T 1 u u, cos (1) 2, cos 2, cos T 2 v v cos (2) cos t w T 3, cos 3, cos 3 (3) w Then the transformaton matrx from global coordnate drecton to th local coordnate s: cos1 cos 2 cos 3 cos 1 cos cos 2 3 cos 1 cos 2 cos 3 The control pont coordnate of th ont n the th local coordnates system can be obtaned as follows: where, T (5) s control pont coordnate of th ont n the global coordnates system; coordnate transformaton matrx of control pont, s a block matrx,.e. T s the t t 0 0 T (6) 0 0 t t (4)

6 X.H. HE et al. / Proceda Engneerng 14 (2011) s the translaton of the orgn of local coordnates system relatve to the orgn of global coordnates system. If the orgn of local coordnates system s located n the M control pont of the th ont, namely M, then: M M, M, M T (7), When calculatng the dsplacement of the th segment from castng poston to matchng poston, the th local coordnates system s frst calculated, then calculatng the coordnates of the 1th ont and th ont n the th and 1th local coordnates system the fnal translaton amounts D as obtaned by: D (8) 1 where, the local coordnates X, Y of M ponts and Z of L, R have control functon, and the other ponts are redundant, but have effects of nspecton. Based on the MATLAB platform, a specal software of precastng geometrc shape control was programmed, whch has been valdated by other commercal software. 4. CASE STUDY 4.1. Precastng geometrc shape control The total length of the elevate brdges on Guangzhou metro lne 4 from south Shawan rver to Jngzhou s around 20 km, nclude dfferent span PC smply supported brdge and 6 contnuous PC brdges. All the brdges were precasted by short-lne method except for several turnout beams usng castn-place method. The standard segment length s 2.5m wth dfferent end segment length for dfferent span smply supported brdge, and 8m to 10 m length of per top segments and 0.95 m to 2.45m closure sectons length for contnuous brdge. In fact, t s dffcult to set control ponts n onts for actual segments. Therefore, n Guangzhou metro lne 4, the sx control ponts nclude 4 elevaton control ponts the vector ( L, R) and two central axes control pont ( M ) were placed onto the segment secton wth 20 cm dstance to segment edges (ont) by usng nals, as shown n Fgure 5. Based on the measurements of sx coordnates and aforementoned coordnate transformaton formula and specal software, the theoretcal relatve locatons of matchng segment were obtaned. Due to measure errors and unavodable locaton change of matchng segment, the constructon error of segment s nevtable, whch can be amended and compensated by adustng the next matchng segment. The precse measurement s very mportant for precast geometrc shape control of short-lne match method Erecton geometrc shape control The erecton geometrc shape control s performed based on the sx pont coordnates of precastng, and the segment erecton qualty s decded by segment precasted qualty n a very large extent. The erecton geometrc shape control of smply supported brdge n Guangzhou metro lne 4 s relatvely easy for usng brdge erectng machne and all segments erected at one tme, as shown n Fgure 6.

7 132 X.H. HE et al. / Proceda Engneerng 14 (2011) Fgure.5 Sx ponts of measure control(unt: mm) Fgure.6 Erecton of smply supported brdge Fgure.7 Erecton of contnuous brdge The contnuous brdges were constructed usng cantlever erecton method (see Fgure 7), and varable cross-secton ncrease the dffcult of segments precastng and erecton. The test erecton s mportant to confrm the adustment quantty for cantlever erecton. After obtanng the adustment quantty, the relatve correct steps such as changng ont epoxy resn adhesve thckness or addng new concrete ont are requred. If the correct quantty s too large to ensure the sx coordnates, the recalculatng s necessary for cantlever erecton geometrc shape control. 5. CONCLUSIONS Guangzhou metro lne 4 vaduct brdges have become a beautful urban landscape and convenent transportaton system for the resdents of south Guangzhou. As the frst tme to use short-lne match method on a large scale n manland of Chna, the applcaton s successful. As long as the geometrc shape control technologes were mastered and extended commendably, and ensure the segment precastng qualty, the short-lne match method must be developed and appled n the brdge constructon n Chna. The desgn and constructon experence of Guangzhou metro lne 4 provde an mportant engneerng reference for correlatve brdges n the future.

8 X.H. HE et al. / Proceda Engneerng 14 (2011) ACKNOWLEDGMENTS The work descrbed n ths paper was supported by grants from the Natonal Scence Foundaton of Chna (Proect No ) and Guangzhou Metro Company (Proect No. J4KC037). REFERENCES [1] Hrosh. (1999). Matsumaru.Htach Conrbutes to Ralway Systems for the 21st Century. Htach Revew, 48(3): [2] John J.Sun, Gernot Komar (2008). Advance Segmental Precast/Prefabrcaton Technology and Its applcaton n Maor Brdge Engneerng. Proceedngs of 2008 Chna Internatonal Hgh-speed Ralway Brdge Technology Exchange Collecton, Beng, pp [3] Pang, S. H. and Gao, W. (2006), The lnear motor vehcle n Guangzhou metro lne 4, J. Urban Rapd Ral Transt, 19(11), (In Chnese). [4] Xong Anshu (2005). Desgn of the Pre-cast Segmental Box Beams of the 4th Guangzhou Metro Lne. Traffc Engneerng and Technology for Natonal Defence, 5, pp (In Chnese).