瑞士布格多夫鐵路橋降噪中使用彈性鋼軌扣件的實驗與理論分析本科畢業(yè)設計外文文獻及譯文

1、本科畢業(yè)設計外文文獻及譯文文獻、資料題目：Structural Design of 文獻、資料來源：網(wǎng)絡文獻、資料發(fā)表（出版）日期：2007.1院 （部）： xxx專 業(yè)： xxx班 級： xxx姓 名： xxx學 號： xxx指導教師： xxx翻譯日期： xxxThe increased noise level as trains travel over bridges is, in many situations, a source of disturbance for nearby residents. As well as the rolling noise radiated by t

2、he wheel and track, the vibration generated at the wheel-rail interface also propagates into the bridge structure and the vibration response of the components of the bridge is an important extra source of noise compared with tracks at-grade. Vibration isolation of the bridge structure from the rail

3、is therefore used to reduce noise. This often takes the form of resilient rail fasteners. Two different elastic rail fastenings were therefore tested on a twin track bridge by the Swiss Railways (SBB). The bridge over the river Emme at Burgdorf, is a ballastless steel bridge with timbers between the

4、 rail fastener and the bridge. Hanging steel sleepers have been added between the wooden sleepers on which the track is supported to form a continuous deck under the track. To find the best elasticity for the rail fasteners, predictions of the bridge noisewere made using the Norbert model. Measureme

5、nts were made on the bridge with thetrack in its original state to provide parameters for the model. These included rail and sleeper vibration as well as pass-by noise from service passenger and freight trains at different speeds. For the two tracks, elastic rail fasteners from two suppliers were in

6、stalled. The measurement after installation showed a clear noise reduction for the frequency range from 80 to 400 Hz of about 10 dB. However the reduction in A-weighted overall noise level is in the range of 2 to 4 dB, as indicated by the model. The results show similar reduction for both systems.Th

7、e main reason for the increase in noise as trains cross a bridge is the vibration of the structure. Here the rolling noise radiated by the track and bridge is studied for the twin track bridge over the River Emme at Burgdorf, Switzerland. Two photographs of the 57m long bridge are shown in Fig 1. Th

8、e track on the bridge takes an unusual form in that steel sleepers have been added between the wooden sleepers on which the track is supported in order to form a continuous deck. The steel sleepers are hung from the rail and are not otherwise supported by the bridge structure.Resilient rail fastener

9、s were installed and the steel sleepers replaced with woodensleepers in October 2006. The reconstruction was accompanied with noise measure-ments in May, October, December 06 and January 07. One track was equipped with resilient fasteners from Pandrol, the other, from Vossloh. The elasticity of the

10、fasten-ers in both cases is about 20MN/m. To identify the effect of the hanging steel sleep-ers, additional noise measurements were carried out on one track after installing theresilient fasteners but before replacing the steel sleepers. To find the best elasticity for the rail fasteners, prediction

11、s of the bridge noisewere made using the ISVR software Norbert (Noise of Railway Bridges and ElevatedStructures) 1. Measurements were made on the track in its original state to provide parameters for the model. Fig. 1. Left: The Burgdorf bridge and track. Right: Arrangement of wooden bearing sleeper

12、s and suspended sleepers. ISVR has developed a bridge noise prediction model calledNorbert based on the combination of an analytical model of the track and a statistical energy analysis method (SEA) for the bridge 2, 3. In this method, the bridge structure is described using a single subsystem type;

13、 plates in bending. It has been found sufficient to use a simplified version of SEA which assumes equipartition of energy. In this assumption the energy is distributed to each of a number of subsystems according to their reso-nant energy capacity resulting in an estimate of the mean squared vibratio

14、n velocity on each susbsystem. For parts of the structure such as the wooden walkways to the side of the tracks on the Burgdorf Bridge, additional networks of subsystems can beadded to the model that are excited by the velocity of particular susbsystems of themain network. The bridge bearings and pi

15、ers are not important for the noise radiation. For the track, the rail support stiffness is an important parameter.The combined roughness of the wheel and rail running surfaces excites the wheeland rail into vibration according to their dynamic properties. Models for the rolling noise emitted by the

16、 wheel and track are well established 4, 5. The way in which the track is assumed to transmit energy to the SEA model of the bridge is an important aspect of the calculation. For the current bridge, a model of the rail coupled via a con-tinuous spring-mass-spring support to the longitudinal beam of

17、the bridge has been used up to the rail-on-sleeper resonance frequency. Above this frequency the forcefrom the track is assumed to drive the local input mobility of the longitudinal beam.The latter is based on an approximate formula for an I-section beam 6. The sound power is calculated from the vib

18、ration velocity of each component via simply calculated radiation ratios for each plate subsystem. Simple propagationcalculations are then used to estimate the sound pressure level at particular receiverlocations.The principles and results of the analysis were compiled in a report for Swiss Railways

19、 7. In the case of the Burgdorf Bridge, the steel sleepers will have a significant effecton the track decay rates and provide an additional radiating component. These effectshave been accounted for with a specially constructed track model. This includes the modal behaviour of the wooden and steel sl

20、eepers modelled as beams. The effect on the decay rates on noise is calculated as correction to the prediction (see 8).2.1 Parameters Derived from Measurements on the Bridge Using Service Trains Fig. 2(a) shows the measured vertical direct receptance at the rail-head. Although the measurement qualit

21、y is poor, especially below 300Hz, the main resonance peak due to the stiffness of the rail support can be clearly seen. The dashed line on Fig. 2(a) shows the calculated receptance using a support stiffness of 240MN/m and a mass per sleeper end of 28kg. In Fig. 2(b) the calculated decay rates are s

22、hown along with the decay rates measured by SBB according to the method described in reference 8. In the measurements of the decay rate responses up to a distance of 7.2m from the excitation have been used. The minimum decay rate measureable with this length of baseline is 0.6dB/m 8. The measured de

23、cay rate is well above this. Fig.2.Comparison of measurement and calculation: left side, vertical point receptance of the rail; right side, decay rates of the rail.An estimation of the combined effective roughness (i.e. combined wheel and rail roughness with the contact filter already accounted for)

24、 is needed for the predictions. A method to determine the combined roughness from rail vibration measurements under traffic is described in reference 9. This method uses the spectrum of vibrationduring a train pass-by and three correction factors. It has been applied to rail vibration measured by th

25、e SBB. The roughness is a function of the brake type of the train. Here, the most important trains to consider are the cast iron block tread-braked freight trains. Two measurements of vertical rail vibration are available from trains travelling at steady speeds of 77km/hr and 72km/hr. Three more are

26、 available for lower speeds that vary during the measurements from about 40 to 60km/hr. The estimates of the combined effective roughness from these records are presented in Fig. 3. They are plotted as a function of frequency corresponding to a train speed of 100km/hr. These roughness spectra are pl

27、otted in comparison with the typical spectra for smooth rail and either cast iron block tread-braked, or disc-braked trains. These are the standard roughness spectra used in the Silent Freight and Silent Track EU projects 10. The roughness assumed for the present calculations is also shown on Fig. 3

28、.Fig. 3. Combined effective roughness spectra derived from measurements compared with those used in the Silent Freight and Silent Track Projects (, calculated from the two faster freight trains; - - - -, calculated from the slower freight trains - - - , SF/ST project combined roughness for tread bra

29、ked and (lower) for disc braked wheel; mean spectrum assumed for current calculations)The microphone positions were, for both tracks: beneath the bridge; 7.5m to the side, 1.2m above the rail head and 25m to the side, 2m above the rail head. These were all in a plane 6m from one end of the bridge. A

30、n additional measurement was made in the 7.5m position adjacent to the track at grade. The details of the measurements can be found in a report 11 for Swiss Railways.Both freight and passenger trains were measured. Only freight trains fully equipped with cast iron brakes are included. All passenger

31、trains were either equipped with composite-block or disc brakes. All passenger trains stopped at the nearby station of Burgdorf resulting in a large range of velocities and some changes of velocity (up to20% in some cases) during measurement. Fig. 4 presents the measurements and predictions for the

32、freight trains for the north and south tracks before and after the installation of the resilient baseplates. Fig. 5 presents the corresponding measurement results for the passenger trains. No predictions were made for the passenger trains. The measurements are the average of freight trains travellin

33、g between 66 and 72km/hr in each case. The predictions are the nearest available at 80km/hr. It can beseen that both baseplate types perform similarly resulting in 5 to 10dB reduction of noise in the 80Hz to 400Hz one-third octave frequency bands. However, around thepeak of the noise spectrum near 5

34、00Hz, smaller reductions are achieved. It is at this frequency and above that the rail noise dominates over the bridge-structure radiatednoise. At 1.6kHz and above the wheel is the dominant noise source and there is very little variation before and after the change was made to the track.Additionally

35、, Fig. 4(a) shows the mean of measurements on the track at-grade. These were made at the slightly lower average speed of 60 km/hr. The noise from thewooden sleepers, which was identified by Twins modelling 7 to dominate below 800Hz, is in this case baffled by the ballast and the ground reflection is

36、 expected to be fairly absorbing. This is in contrast to the open bridge structure and the reflection of the water surface. Additionally there is no control of the rail roughness accounted for in the comparison. Despite these differences, it can be observed that the bridge noise has been lowered to

37、levels similar to those of the at-grade track in the frequency bands up to 250Hz. The rail noise component is clearly much lower from the at-gradetrack than from the bridge (800Hz to 1.25kHz).Fig. 4. Comparison of predictions with measurements of average of freight trains; (a) north track; (b) south

38、 track (, measured before; , measured after, , predicted before; - - -, predicted after, (a) measured at at-grade track, (b) measured at the bridge with the steel sleepers and resilient baseplates)Fig. 5. Average of measurements of passenger trains; (a) north track; (b) south track (, before; - - -,

39、 after, right graph, measured at the bridge with the steel sleepers still in place but with resilient baseplates installed)Fig. 4(b) presents the noise measured when the resilient baseplates had been in-stalled but the steel sleepers had not yet been replaced. It shows that the reductionachieved by

40、the baseplates in the 80 to 400Hz range is compromised by the steel sleepers by around 2 to 3dB.The results for the passenger trains shown in (Fig. 5) indicate the same trends as the freight trains. The 1kHz peak in the spectrum of noise from the south track is probably equipment noise from the trai

41、ns travelling in this direction. The bridge is shown to give much higher levels of noise than nearby track at grade. The installation of resilient baseplates has reduced the overall level difference from about 11dBA to about 8dBA. However, the baseplates make of greater noise reduction of 5 to 10dB

42、where the bridge structure-radiated noise dominates between 80 and 400Hz. The Norbert model has predicted the reduction in noise in the 80 400Hz bands reasonably well although the measured spectra are smoother than those predicted. In the 630 and 800Hz bands, where the rail noise dominates,Norbert h

43、as predicted a reduction that is greater than that actually achieved. This leaves the overall noise reduction to be only about 3dB (4dB predicted) for the freight and passenger trains alike. The removal of the hanging steel sleepers was worthwhile to gain the full benefit of the structure noise redu

44、ction Promising locations for similar bridge treatments will be identified according to their cost benefit. The baseplates from different suppliers to the same specification produce similar results.The authors are grateful to the SBB for permission to publish this work.1Bewes, O.G., Thompson, D.J.,

45、Jones, C.J.C., Wang, A.: Calculation of noise from railway bridges and viaducts: Experimental validation of a rapid calculation model. Journal of Sound and Vibration 293, 933943 (2006) 2Janssens, M.H.A., Thompson, D.J.: A calculation model for the noise from steel railway bridges. Journal of Sound a

46、nd Vibration 193, 295305 (1996) 3Harrison, M.F., Thompson, D.J., Jones, C.J.C.: The calculation of noise from railway viaducts and bridges. Proc. Institution Mechanical Engineers, Part F (Journal of rail and rapid transit) 214, 125134 (2000) 4Thompson, D.J., Hemsworth, B., Vincent, N.: Experimental

47、validation of the TWINS prediction program for rolling noise, part 1: Description of the model and method. Journal of Sound and Vibration 193, 123135 (1996) 5Thompson, D.J., Jones, C.J.C.: A review of the modelling of wheel/rail noise method. Journal of Sound and Vibration 231(3), 519536 (2000) 6Bew

48、es, O., Thompson, D.J., Jones, C.J.C.: Calculation of noise from railway bridges: The mobility of beams at high frequencies. Structural dynamics: Recent advances. In: Proceedings of the 8th International conference, Institute of Sound and Vibration Research, Southampton, (paper 64 on CD ROM) July 14

49、16 (2003) 7Jones, C.J.C., Thompson, D.J.: Acoustic analysis of Burgdorf bridge, ISVR contract report no 06/03, University of Southampton (2006) 8Jones, C.J.C., Thompson, D.J., Diehl, R.J.: The use of decay rates to analyse the performance of railway track in rolling noise generation. Journal of Soun

50、d and Vibration 293(35), 485495 (2006) 9Janssens, M.H.A., Dittrich, M.G., de Beer, F.G., Jones, C.J.C.: Railway noise measurement method for pass-by noise, total effective roughness, transfer functions and track spatial decay. Journal of Sound and Vibration 293(3-5), 10071028 (2006) 10Bouvet, P., Vi

51、ncent, N., Coblenz, A., Demilly, F.: Optimisation of resilient wheels for rolling noise control. Journal of Sound and Vibration 231(3), 765777 (2000)11Muff, W., Grolimund & Partner AG, SBB Stahlbrcke Burgdorf, Lrmmessungen vor und nach der Sanierung, Bern (2007) B.Schulte-Werning et al.(Eds.):Noise

52、and Vibration Mitigation,NNFM99,pp.208-214,2008. Springer-Verlag Berlin Heidelberg2008中文譯文:瑞士布格多夫鐵路橋降噪中使用彈性鋼軌扣件的實驗與理論分析京都議定書Kstli1，聯(lián)席會議Jones2，瑞士和DJ Thompson1聯(lián)邦鐵路SBB, I-FW-PS, Schanzenstr. 5 CH-3000 Bern 65, 瑞士電話：+41（0）51 220 4699傳真：。+41（0）51 220 5014kornel.koestli sbb.ch2南安普敦，ISVR，海菲爾德南安普敦，SO17 1BJ大

53、學南安普敦，UK電話：+44（0）2380 593224，傳真：。+44（0）2380 593190cjcjisvr.soton.ac.uk綜 述在大多情況下，當火車從橋上通過時，增加的噪聲水平就成為了對附近居民的干擾源。車輪和軌道發(fā)出的滾動噪聲，以及輪軌接口處產(chǎn)生的振動在橋的結(jié)構(gòu)中傳播。與地面軌道相比，橋的部件的震動響應成為了另一個重要的噪聲源頭。因此，從鐵路橋梁結(jié)構(gòu)的隔震被用來降低噪聲，往往為彈性鋼軌扣件的形式。因此，由瑞士鐵路（國鐵）在雙軌的橋梁上對兩種不同的鋼軌扣件進行了測試。橫跨布格多夫的艾蒙河的橋梁，是一座無碎石鋼橋，軌道扣件和橋梁之間使用了木質(zhì)材料。吊鋼枕木被添加在支撐著軌道的木

54、質(zhì)枕木之中，以便在軌道下形成一個連續(xù)甲板。為了找到最佳彈性的鐵路扣件，借助諾伯特模型，橋梁噪聲被進行了預測。測量是在擁有原始狀態(tài)的軌道的橋梁上進行的，來為模型提供參數(shù)。其中包括鐵路和軌枕振動，以及來自以不同速度經(jīng)過的客運和貨運列車的噪聲。來自兩個供應商的鋼軌扣件被安裝了在了兩個軌道。安裝后的測量結(jié)果顯示頻率范圍從80到400赫茲的噪聲明顯降低了約10 分貝。然而，如模型所示，在A -加權(quán)的總噪聲水平下降的范圍是在2至4分貝。結(jié)果表明這兩個系統(tǒng)噪聲降低情況類似。1 簡介火車穿過大橋時，噪聲上升的主要原因是結(jié)構(gòu)的振動。下面是研究了橫跨在瑞士布格多夫的艾蒙河上的雙軌橋梁的軌道和橋梁的滾動噪聲輻射。圖

55、1為這座57米長的橋的兩張照片。橋的軌道中，鋼材被加在支撐軌道的枕木之間以形成一個連續(xù)的甲板木軌枕補充。鋼鐵軌枕吊在鐵路，不另行被橋梁結(jié)構(gòu)支撐。2006年10月彈性鋼軌扣件被安裝，鋼材枕木取代木質(zhì)枕木。重建與噪聲測量進行于5月，10月，12月6日和1月7日。一條軌道被裝備來自Pandrol的彈性扣件，另一條的來自Vossloh。在這兩種情況下扣件的彈性約為20MN /米。要確定懸鋼的效果，在安裝彈性扣件之后，更換鋼軌枕之前，需進行額外的噪聲測量。為了找到最佳彈性的鐵路扣件，使用ISVR軟件諾伯特（噪音和高架鐵路橋梁結(jié)構(gòu)）進行了橋梁噪聲預測1。測量了在其原始狀態(tài)的軌道，為模型提供參數(shù)。圖. 1.

56、左圖: 布格多夫橋與軌道。 右圖:木枕與鋼枕的安裝。2 建模ISVR開發(fā)了橋梁噪聲預測模型諾伯特，該模型以一個對軌道的分析模型和一個橋梁統(tǒng)計能量分析法的 2，3（SEA）組合為基礎。在此方法中，橋梁結(jié)構(gòu)被用一個單獨的子系統(tǒng)類型描述，板彎曲。人們已經(jīng)發(fā)現(xiàn)足以使用的海簡化版本，承擔能量均分。在這個假設中，能量根據(jù)自己的諧振能量的最大承受力被分配給每一個子系統(tǒng)，從而導致對每個子系統(tǒng)平均每平方振動速度的估計。對于結(jié)構(gòu)部件，如在布格多夫大橋上的鐵軌旁的木制人行道，其他子系統(tǒng)的網(wǎng)絡可以被添加到一個模型，該模型被主要網(wǎng)絡的特別子系統(tǒng)的速率刺激。橋梁支座和橋墩對于噪聲射輻都不重要。對于軌道，是一個重要參數(shù)。根

57、據(jù)其動態(tài)特性，車輪軌道運行表面粗糙度激發(fā)振動。車輪與軌道發(fā)出滾動噪聲的模型被完美確立4，5。一個軌道被假設將能量傳送到跨海大橋模型的方法是計算的一個重要方面。對于目前的大橋，一個通過連續(xù)的彈簧質(zhì)量彈簧來支持橋梁縱梁的鐵路模型已經(jīng)被使用到軌上枕木共振頻率。超過這個頻率來自軌道的力被假定驅(qū)動本地縱梁流動性的輸入。后者為基于一個I型橋梁的近似計算公式6。聲功率是由每個組件的振動速度通過簡單計算每盤子系統(tǒng)的輻射率可得。簡單傳播的計算，然后被用來估計在特定接收地點的聲壓水平。原則和分析結(jié)果，被編譯于一份瑞士鐵路報告中。就布格多夫大橋而言，鋼枕木將對軌道噪聲衰減率有顯著影響，并為其提供一個額外的散熱元件。這些影響已用一個專門建造的軌道模型說明解釋。這包括木軌枕和鋼軌枕為橋梁的模態(tài)行為。對噪聲衰退率的影響被計算作為預測的校正（見8）。8中描述的方法SBB測量得到的衰退率被呈現(xiàn)出來。在衰退率的測量中，遠達7.2米激發(fā)距離已被使用。使用這一基線長度，衰退率可測最低值為圖2：比較測量和計算路衰變率：左側(cè)為鐵路垂直接收點;右側(cè)為鐵路衰變率。對預測來說，一個對有效粗糙結(jié)合的估計是必要的。一個用來確定交通繁忙時來自鐵路振動測量的結(jié)合粗糙度的方法為文獻9中所描述。此方法利用一輛火車經(jīng)過時的振動光譜和三個校正因子。它已被SBB應用到鐵路的振動的測量。中，所有客運列車停在了布格