civil-engineering-(土木工程概论英文课件)CHAPTER-SEVEN

1、CHAPTER SEVENTUNNEL ENGINEERING7. 1 Introduction· A tunnel is a long, narrow, essentially linear excavated发掘；挖掘underground opening, the length of which greatly exceeds its width or height. For centuries, mankind has excavated tunnels in the earth for a myriad （a large indefinite number） of uses

2、. With improvements in design and construction, the diversity of uses has also widened，and tunnels are not simply the mines and shelters they used to be. Nowadays a great deal of countries are using tunnels to provide spaces for human activities such as living, storage, communication, power transmis

3、sion and transportation. In the past fifty years, China has made great achievements in the construction of railway tunnels, highway tunnels, metros地铁, hydraulic tunnels and underground powerhouses（动力室；发电所an electrical generating station） More than twenty railway tunnels longer than 5km and three rai

4、lway tunnels longer than 10km have been built or are under construction. China also built a large number of railway tunnels in difficult geology, such as Dayaoshan railway tunnel, which is 14. 295km located in Hunan Province. In the mainland of China, there have been more than 5300 railway tunnels w

5、ith a total length of 2500km, ranking first名列第一 in the world up to now. Although the extensive construction of highway tunnels started rather late compared with that of railway tunnels in China, the number of highway tunnels has increased rapidly in the recent years due to the new tide of constructi

6、on of high class highways or expressways.At present, there are more than 500 highway tunnels with a total length of more than 130km, of which about 90 tunnels have a length of over 1km each and 6 tunnels over 4km each, the longest highway tunnel in China now is the 4. 7km of Huayinshan Tunnel in sic

7、huan Province. Besides those tunnels already built or under construction, several long highway tunnels are under design or planning. For example , one is the 8.6km long Xingkui Tunnel in Fujian Province.It is well worth mentioning that three immersed highway tunnels, which are located in Guangzhou Y

8、ongjiang and Shanghai respectively also have been designed and built by Chinese companies. There has been more than 100km of metros built in five cities, namely Beijing, Shanghai, Tianjin, Guangzhou and Nanjing. The construction techniques of tunnels and stations have got great advances in the Shang

9、hai metro and Guangzhou metro, where the shield tunnelling method has been successfully used. In the respect of hydraulic tunnels, there are now more than 400 tunnels with a length of more than 400km and more than 40 underground powerhouses. For example, the diversion tunnel in Ertan hydro-power sta

10、tion is 1100m in length, 23m in width and 17. 5m in height, which is the largest tunnel in China. In the construction of hydraulic tunnels and expressway(高速公路 a broad highway designed for high-speed traffic) tunnels, international competitive bidding竞标；竞争性招标 is usually adopted, which promotes the im

11、port and application of advanced technology and equipment, for example, wet shotcrete喷浆混凝土；喷射水泥砂浆, TBM and DOT have been widely used in tunnels and metros in China.Tunnels are one of the greatest projects in engineering and construction. It is also one of the most expensive projects. For this reason

12、, extensive planning and surveying goes into the pre-excavation stage of the project.7.2 Tunnel Types and Tunnel Structures7.2. 1 Tunnel TypesThe response of the ground to the excavation of an opening can vary widely. Based on the type of ground in which tunnelling takes place, four principal types

13、of tunnelling挖隧道may be defined:(1) Cut-and-cover随挖随填法 tunnelling shown in Fig. 7. 1. In such tunnelling the ground acts only passively as a dead load applied to a tunnel which is to be erected like any aboveground engineering structureFig. 7. 1 Cut and Cover Tunnels.· (2) Soft ground tunnelling

14、 shown in Fig. 7.2. In such tunnelling immediate supports直接支援 must be provided by a stiff lining. The ground usually participates actively积极地；活跃地in an active manner by providing resistance to对的抵抗 the outward deformation of the lining.Fig. 7. 2 Soft Ground Immersed Tunnel (Source: Photo provided by N

15、ingbo Changhong Tunne! Co. )· (3) Medium-hard rock tunnelling shown in Fig. 7. 3. In such tunnelling, the tunnels are constructed in medium-hard rocks or in more cohesive soils粘性土壤 , where the ground may be strong enough to allow a certain open section at the tunnel face, A certain amount of一定数

16、量的 stress release应力释放；应力消除 may permanently be valid before the supporting elements and the lining begin acting effectively. In this situation only a fraction of the primary ground pressure is acting on the lining.Fig, 7. 3 Muti-face Tunnelling in Medium-hard Rock (Sources Photo provided by Dr. Zixin

17、 Zhang)· (4) Hard rock tunnelling挖隧道 shown in Fig. 7. 4. In such tunnelling the bird rock ground may preserve the stability of the excavation the act of digging so that only a thin lining细线 will be necessary.Fig. 7. 4 Hard Rock Tunnelling (Sourcei Photo provided by Dr. Zixin Zhang)7.2.2 Tunnel

18、Structures· In the design of tunnels, designers attempt to utilize a structure that will prove to be highly effective, Basic mechanics in conjunction with连同，共同；与协力连同，共同；与协力in union, in chorus· the character of rocks or soils, can dictate a most effective structure. For instance, tunnels ar

19、e rarely excavated with a flat roof屋顶平台. The reason is that, as span increases, the rock or soil in the center part of the span has less force holding it up, and the flat-roofed建筑物等平顶的tunnel is more susceptible to collapse. Therefore, for the most part在极大程度上in large part; mainly or chiefly, tunnels

20、are excavated with circular arched圆拱roofs, which are the most stable structures with regard to externally applied loads外加负载. For this reason tunnels are commonly constructed with circle shaped , horseshoe shaped sections or with gothic arch哥特式尖拱 roofs, which provide maximum stability.In addition to

21、the shape of tunnel sections, the structure and size are also very important. Doubling the diameter of a tunnel requires removing four times as much soil or rock, the surface area of the tunnel is doubled and the forces of the soil or rock are now over twice. So the use of supporting structures is m

22、uch more important in large tunnels than in smaller ones. Often, in cases where tunnels are to be driven into rock of questionable可疑的；有问题的competence, very small tunnels are driven first and then carefully enlarged and supported as shown in Fig. 7. 5.· With respect to shield-driven防御；起保护作用heat s

23、hield 热屏；（航天器的）防热罩 sword and shield 剑与盾 wind shield 遮风屏；减阻帽 water shield 莼菜；防水罩，挡泥板；密封条 protective shield 防护屏；防护板 hydraulic shield 液压防护装置 radiation shield 辐射防护屏 cable shield 电缆包皮；电缆的输入套管；电缆护套 shield gas 保护气体 tax shield 税收挡避 under shield 废语在鏖战中   thermal shield 隔热，热屏蔽 canadian shield 加拿大地盾 shiel

24、d cable 屏敝电缆；屏蔽线   更多收起词组短语 n.盾；防护物；保护者dong, fenderingvt.遮蔽；包庇；避开；保卫avoid, shadow, guard, curtainvi.防御；起保护作用protect sb./sth. from sth. tunnels often used in soft soils, the structures ofthe tunnels are as follows:(1) Circle structures· This type of shield-driven tunnel is widely used in co

25、nstructing metros地铁in soft ground软弱地基and has a number of advantages compared with other types of structures. First and foremost首先；首要的是, the circle structure is more economical and very convenient in construction. The driving shield machines are easy to be made and operated and more reasonable in dis

26、tribution of internal forces内力compared with other structure shapes.Rectangular矩形的；成直角的rectangular plate 矩形板；长方盘 rectangular section 矩形剖面 rectangular waveguide 矩形波导 rectangular coordinate 直角坐标；矩形座标 rectangular coordinate system 直角坐标系 rectangular wave 电子矩形波 rectangular tube 矩形管，方形管；矩形断面管；长方通；方通 rectan

27、gular block 长方体，矩形块 rectangular pulse 矩形脉冲 rectangular table 长方桌   更多收起词组短语 adj.数矩形的；成直角的quartering(2) and horseshoe U形物 structuresThis type of structure is not widely adopted since it is more complicated and expensive. Furthermore, the distribution of internal forces is not simple either.(3) D

28、OT structuresThe DOT structure shield has just come to Shanghai and will be used widely it the construction of metros. Fig. 7. 6 illustrates the structure of it.Fig. 7. 6 Structure of dot Shield7. 3 Construction of Tunnels7.3.1 Railway Tunnel· Among the 5300 railway tunnels in China, most of th

29、em have been constructed using the NATM (New Austrian Tunnelling Method) method. NATM was firstly adopted in the Xiaken Railway Tunnel of Wanggang Railway. The tunnel with a length of 65m and a depth of 20m was constructed in heavily weathered风化的；倾斜的strata层；地层；阶层, where rocks are not only weak and f

30、ractured but also rich in groundwater. On the basis of the principles of NATM, the tunnel was excavated in a large cross section by use of pre-split blasting爆炸；破坏or smooth blasting for minimizing disturbance to the surrounding rock. After excavation挖掘，发掘, bolts and shotcrete喷浆混凝土；喷射水泥砂浆n.喷浆混凝土；喷射水泥砂

31、浆gunite concrete, jetcrete· were immediately mounted安装to control the deformation of the surrounding rock and a secondary concrete lining混凝土衬砌was mounted when the deformation of the surrounding rock was basically stable. During the construction, the surrounding rock was monitored and the constru

32、ction was adjusted according to the monitoring results. The successful experience of NATM in the Xiaken Railway Tunnel铁路隧道 has been introduced rapidly to other railway tunnels. At present, NATM has become the most popular principle on the design and construction of tunnels in China. Chinese engineer

33、s have built considerable tunnels in difficult geology by means of NATM, which has enriched their experience of using NATM. For example, the construction of the tunnels on Nanling-Kunming railway which was opened into operation in 1997 is a typical example in unfavorable geology. There are 258 tunne

34、ls with a total length of 194. 6km that have used NATM. During the construction of the tunnels, difficulties, such as weak surrounding rock, high geostress地应力, shallow浅的；肤浅的depth, uneven pressure, karst喀斯特地形（石灰岩地区常见的地形）karst cave 岩溶洞 karst landform 岩溶地貌；喀斯特地貌 karst topography 岩溶地形；岩溶地势；喀斯特地形 ·

35、, water inflow, faults, concerted gas and high seismic intensity, have been overcome one after another. The completion of Nanling-Kunming Railway demonstrates-that China has capability of building tunnels in almost all unfavorable conditions of geology.Although a large number of railway tunnels have

36、 been built in China, by use of drill and blast爆炸 except the Qinling Tunnel which was constructed by TBM method, it is clear that other construction methods such as shield method and the method of immersed tunnels shall also be adopted for building some railway tunnels in special geology.7.3.2 Highw

37、ay Tunnels· On the basis of the experience drawn from从中得到；从提取 the construction of railway tunnels , the highway department has successfully designed highway tunnels with large cross sections and underwater and has accumulated much experience on the construction of these tunnels.(1) Highway tunn

38、els with large cross sectionsBuilding three lane小巷；航线；车道 highway tunnels is unavoidable with the construction of six-lane expressway高速公路. In China, several tunnels with three lanes are finished, which are Shanxinpo Tunnel in Yunnan, Kaoyishan Tunnel in Guangzhou, Tieshanping Tunnel and Zhenwushan Tu

39、nnel in Sichuan and Tanyugou Tunnel in Beijing,etc. The highway department has conducted several research projects on the calculation of structures, excavation and support measures of three-lane tunnels and has obtained a number of useful research findings which have been used in the construction of

40、 the above tunnels.(2) Highway tunnels underwater· Dapulu Tunnel, 2761m long, passing through穿越 under the Huangpujiang River in southeast Shanghai, was opened to traffic in 1970. This tunnel is the first highway tunnel under river constructed by shield in China, as shown in Fig. 7. 7.This shiel

41、d used for the tunnel is an 11. 26m diameter mesh type mechanized shield machine with a hydraulic mucking system.· On May 1,1989, another tunnel, the 2261m long Yan'an Donglu Tunnel passing under the Huangpujiang River, was put into service交付使用；使工作（运转）, which was bored by the same kind of s

42、hield used in Dapulu Tunnel. Due to the economic development and traffic increment增量；增加；增额；盈余 in Pudong浦东 area, the third tunnel under huangpujiang River, which is 2173m in length and called the secondary Yan'an Donglu Tunnel,was constructed by shield and opened to traffic in 1996. The experienc

43、e from the construction of the three tunnels will be precious for the future construction of large diameter highway tunnels under river by shield.In addition, on January 8, 1994, the first immersed tunnel沉埋式隧道 in China, i,e. the Zhujiang Immersed Tunnel in Guangzhou, was put into operation, which wa

44、s designed and built by Chinese companies. The tunnel with a width of 33m and a height of 7. 96m is 1239m in the total length including 517. 5m approaches on both banks 264m was bored by the use of mining method and 457m by use of the immersed浸入的；专注的method It consists of two chambers for highway, wi

45、th two lanes for each, one chamber for metro and one small chamber for cables.·Fig. 7. 7 Dapulu Tunnel (Source: Photo provided by www. people. com. cn, 2001)· with regard to the immersed method in detail, the first section of the tunnel will probably be placed on the one side of the site,

46、but before this can be undertaken, a great deal of preparatory work准备工作 has to be done. During the prefabrication预加工；预先制造 of the tunnel elements the site entrance入口；进入 portal will be constructed. A trench long enough to receive tunnel elements will be dredged from the one side of the site. When this

47、 is completed the first element can be manoeuvred over the trench and is ready to be gently lowered into position against the site portal The lowering operation requires a high degree of precision to avoid making damage to the elements and to ensure that a reliable water tight水密；水密的 seal is made wit

48、h the portal大门，入口 or preceding tunnel elements. Finally, the trench is infilled and topped with a layer of rock armour to provide protection for the tunnelfig7. 8 Coustruction Sequence for Immersed tunnelmethod and the mining method was adopted for the construction of metros so as to reduce the dist

49、urbance to surface traffic and citizens, lives and to avoid the relocation of surface buildings, underground cables and pipes.During the construction of the first line of the Shanghai metro (Figure 7.10 ), seven shields were imported from aboard for the driving of running tunnels under busy streets

50、or high buildings. The advance rate of the shields are 46m per day on an average, 150m per month on an average and 320m per month in maximum. In the early 1990's, the shield method was also used in the construction of the running tunnels on the first line of Guangzhou metro.Fig. 7. 10 Shanghai M

51、etro Constructed by Shield MethodBesides the shield method, NATM was widely adopted for the construction of both running tunnels and stations in the Fuxingmen Bawangfeng line of Beijing Metro and the first line of Guangzhou Metro between the 1980's and 1990's. NATM is still a most important

52、method used in the construction of metros in China.In the construction of stations, the application of cut and cover method锄坑回填法 has increased in recent years in China. The cut and cover method was used in the construction of three stations in the first line of Shanghai Metro in the early 1990 s and

53、 was later adopted for the construction on Fuxingmen Bawangfeng line of Beijing Metro and the first line of Guangzhou Metro.7.3.4 Hydraulic and Underground PowerhousesIn the construction of hydraulic tunnels and underground powerhouses动力室；发电所, there are three example projects in China:· (I) Tia

54、nshengqiao hydro-power station built in the I980's, includes three division tunnels, each with a diameter of 10. 4m and a length of 9. 78km, which were constructed in the strata地层；阶层 of developed karat克拉. In order to speed up the advance rate of excavation, two second-hand tunnel boring machines

55、 (TBMs) with a diameter of 10. 8m were imported from aboard (Figure 7. 11). Due to unfavorable geology, such as karst debris flow 地质 泥石流 and underground rivers , the construction went slowly and was completed behind schedule.Fig. 7. 11 Tunnel Boring Machine (TBM) (Source: Tunnel Boring Machine, htm,

56、 2003)(4) Gansu Yindaruqin division project was constructed in the early 1990's, with a length of 11. 649km and a diameter of 5. 53m. By use of double shield TBM, the construction of the tunnel was completed in 13. 5 months. With a best daily progressing rate of 65. 5m and a best monthly rate of 1300m, the TBM method has aroused general interest in China. After that, the Ministry of Railways铁道部，铁路