Abstract

The floating transportation of tunnel elements is a crucial link in the construction of submerged pipe tunnels. However, the selection of towing water resistance coefficient is always one of the difficult problems, so that the tank towing test is generally used to determine the value in major projects. This paper takes the long and large tunnel element as the research object, the coefficient of towing water resistance of tunnel elements is regressed according to the towing test data of the physical model of towing tank tunnel elements. The empirical formula of drag coefficient of tunnel elements towing in water is obtained, which is composed of such variables as channel water depth, towing velocity and towing angle. The empirical formula is compared with the experimental value of tunnel elements towage test, and the result is close to the experimental value. It is shown that this empirical formula can calculate the towing water resistance coefficient of tunnel elements towing more quickly and accurately. The empirical formula can provide a new method to estimate the towing water resistance coefficient of towing for the subsequent towing of long and large tunnel element and slender and long floating bodies, and then provide suggestions for towing for project bidding, and provide support for the scheme planning of ship machinery configuration and construction decision making.

Introduction

Immersed tunnel elements have been increasingly used all over the world with extensive application range. There are over 130 underwater immersed tunnel elements fully operational worldwide right now. The Detroit River Tunnel is the first immersed tunnel element built in accordance with the standard construction method of immersed tunnel element; Japanese government started to build immersed tunnel elements since 1935, and has built a large number of large-scale immersed tunnel elements in the past three decades; the construction of the Maastunnel in Rotterdam, Netherlands started in 1941; the Busan-Geoje immersed tunnel was built in recent years, the maximum weight of a single tunnel element even reached 50000 tons while the maximum immersion depth was 40m. Researchers in Chinese mainland started research on this construction method in Shanghai around 1960. Although compared to other countries, the construction of the immersed tunnel element in China started late, it enjoys fast development and good momentum. The construction of the Pearl River Tunnel was completed in 1994; Ningbo Yongjiang Tunnel and Changhong Immersed Tunnel were completely built in 1995 and 2002, respectively; the construction of Guangzhou Luntou-Biological Island Immersed tunnel element was completed in 2010; Zhoutouzui Tunnel in Guangzhou was opened in 2015; 2017 witnessed the construction completion of Honggu Tunnel in Nanchang and Dongping Tunnel in Foshan; the Hong Kong-Zhuhai-Macao Bridge consisting of bridges, tunnels and artificial islands was officially opened on October 23, 2018, making the travel among Hong Kong, Zhuhai and Macau much more convenient and also promoting the prosperity and development of Hong Kong, Zhuhai and Macao; immersed tunnel element has been adopted by a series of key projects including Shenzhen-Zhongshan Link, Jinguang East Tunnel, the river-crossing tunnel of Yuliangzhou of Xiangyang East-West Axis, Immersed Tunnels Project of Chebei Road-East Xinjiao Road, Dalian Bay Subsea Tunnel, Guangzhou-Shenzhen Riverside Expressway and Guangzhou Ruyifang Station, which proves the broad prospect of immersed tunnel element.

This content is only available via PDF.
You can access this article if you purchase or spend a download.