Comparative studies on the performance of a roadheader, impact hammer and drilling and blasting method in the excavation of metro station tunnels in Istanbul

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Abstract

Drilling and blasting is the most widely used excavation method in mining and tunnelling especially in hard rock conditions. But in recent years, the application of roadheaders and impact hammers in hard rock, especially in fractured geological formations has increased considerably. However, it is strongly emphasized that the prediction of the machine performance plays an important role in the time scheduling and in the economy of tunnelling projects and accumulated data will serve a sound basis for performance prediction models.

This paper presents information on Istanbul Kadikoy–Kartal metro tunnels which are planned to be constructed in two stages, the first one which is in Kozyatagi–Kadikoy direction and the second in Kozyatagi–Kartal direction. The construction method of the Kozyatagi–Kadikoy station tunnels is first summarized and later, the performance of a roadheader, impact hammer and the results of drilling and blasting methods are compared.

The results of this study show that machine utilization time is 28.2% for roadheader and 14.2% for impact hammers. Average net cutting rates (NCR) are 32.26 m3/h for roadheader (218.3 m3/day), net breaking rate (NBR) 13.1 m3/h (45 m3/day) for impact hammers and production rate with drill and blast method (D&B) is found to be 187 m3/day.

Introduction

The use of TBMs is found unfavourable in short tunnels and in these cases drilling and blasting method is preferred, however, this method is restricted in urban areas. In favourable conditions, roadheader and impact hammer are preferred due to many advantages over conventional methods. These include improved safety, minimal ground disturbances, elimination of blast vibration, reduced ventilation requirements and cost. Therefore, hydraulic impact hammers have been used widely in metro tunnelling projects in Istanbul since 1992. However, roadheaders have been also used in Taksim–Levent and Kadikoy–Kartal metro tunnels in some extend (Bilgin et al., 2002, Ocak et al., 2007).

Although many researchers investigated the factors affecting the performance of roadheaders and impact hammers it is believed that new published data will improve existing performance prediction models. (Bilgin et al., 1996, Bilgin et al., 1997, Bilgin et al., 2002, Bilgin et al., 2005, Bilgin et al., 2007, Copur et al., 1998, Thuro and Plinninger, 1998, Thuro and Plinninger, 1999, Tumac et al., 2007, Ocak et al., 2007, Tuncdemir, 2007, Ocak, 2007, Ocak, 2008). The main objective of this paper is to contribute to accumulated and published data from various tunnelling projects in Istanbul in order to improve predicting the machine performance to schedule and plan the tunnelling projects and determine the excavation efficiency.

The performances of a roadheader (Westfalia WAV 178) and impact hammer (MB 1700) mounted on the carriers, Volvo EC210B, Sumitomo SH200LC, and Caterpillar 3066T, are investigated. The main rock formations of study areas were Trakya and Kartal formations. The first stage of the project is commissioned to Yapi Merkezi–Yuksel–Dogus–Yenigun–Belen consortium. The metro tunnels are being currently excavated by two Herenknecht TBMs of 6.5 m diameter, detailed information about these machines may be found elsewhere (Bilgin et al., 2007). NATM is used only in the excavation of station tunnels which is the subject of this paper.

Section snippets

Description of the metro tunnel project

The population of Istanbul is approximately 14 million and one third of this population lives in Anatolian side. The project of Kartal metro system is planned to meet the enormous transportation demand between East and West of Istanbul. The project will be integrated with Marmaray Project, which is under construction and which will connect European and Anatolian sides at Ibrahimaga station (Fig. 1).

The project of Kadikoy–Kartal metro system starts from Kadikoy square, joins the station of

Site geology

Tunnels between Kozyatagi–Kadikoy are excavated generally in Trakya and Kartal formations (Fig. 2). Trakya formation of carboniferous age consists of sandstone–siltstone–claystone–mudstone–shale in sequences. Limestone and conglomerates layers are also rarely observed. Diabase and andesite dykes having some 10 m thickness are frequently encountered. In the east of tunnel alignment, Kartal formation of Devonian age is found. Kartal formation consists of fine-grained, laminated, fractured and

Comparison of the performance of different excavation methods

The tunnel excavation of the first stage (Kozyatagi–Kadikoy) started in May 2005 with two TBMs and still continues. Impact hammers is used in the excavation of the station tunnels having length of 180 m. Roadheader is only used in Kozyatagi Station due to technical difficulties such as excessive cutter consumption and difficulty in transporting the machine within short length of station tunnels. Excavating machines are seen in Fig. 3 and main characteristics are given in Table 3, Table 4. The

Comparison of recorded machine performances

Field values of NCR for roadheader and NBR for impact hammer are compared with predicted values using some prediction models. Bilgin developed a model based on data collected from different tunnelling projects carried out in Istanbul. Eqs. (1), (2) given by Bilgin are for estimating NBR of impact hammers and Eqs. (2), (3) are for estimating NCR of roadheaders, especially for axial type roadheaders (Bilgin et al., 1996, Bilgin et al., 1997, Bilgin et al., 2002). Copur developed Eqs. (4), (5) for

Conclusions

This study gives a unique opportunity to compare impact hammers and roadheaders with conventional drilling and blasting method. It is emphasized that drilling and blasting method is most efficient method in high strength rocks. Although blasting in urban area is restricted due to vibrations and difficulties in transport of blasting agents, in extreme conditions its use becomes a necessity. Roadheader is proved to be more efficient than impact hammer in terms of machine utilization time and

References (24)

  • N. Bilgin et al.

    The performance prediction of impact hammers from Schmidt hammer rebound values in Istanbul metro tunnel drivages

    Tunnelling and Underground Space Technology

    (2002)
  • A. Lislerud

    Hard rock tunnel boring: prognossis and costs

    Tunnelling and Underground Space Technology

    (1988)
  • J.T. Anderson et al.

    Rock excavation with boom mounted hydraulic hammers

  • Bilgin, N., Yazici, S., Eskikaya, S., 1996. A model to predict the performance of roadheaders and impact hammers in...
  • Bilgin, N., Kuzu, C., Eskikaya, S., 1997. Cutting performance of rock hammers and roadheaders in Istanbul Metro...
  • Bilgin, N., Tumac, D., Feridunoglu, C., Karakas, A.R., Akgul, M., 2005. The performance of a roadheader in high...
  • N. Bilgin et al.

    The determination of some design parameters and performance prediction of tunnel boring machines based on rock cutting tests in Kadikoy metro tunnels

  • B.H.G. Brady et al.

    Rock Mechanics for Underground Mining

    (1985)
  • E.T. Brown

    Rock Characterization Testing and Monitoring, ISRM Suggested Methods

    (1981)
  • Bruland. A., 1988. Norwegian Institute of Technology, University of Trondheim, 1988, Project Report 1-E 98, Hard Rock...
  • H. Copur et al.

    Roadheader applications in mining and tunneling

    Mining Engineering

    (1998)
  • I. Evans et al.

    The Strength, Fracture and Workability of Coal

    (1966)
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