Foreword

The Zhengzhou-Xi’an passenger dedicated railway operated since 2010，as the major component for “four vertical and four horizontal”passenger dedicated railway network，is the first high-speed railway which connects the middle-China with western China.The total length of the railway is about 484 km，and the CRTSⅡbi-block ballastless track structure is applied to the whole line.The prefabricated bi-block sleeper is embedded in concrete poured in advance by mechanical vibrating method，and the integrated ballast bed of continuous and even reinforced concrete will be formed at one time，with the frame to fix track panel and supporting foot to locating cross girder.

The book falls into ten chapters，the CRTSⅡbi-block ballastless track construction technology is introduced and explained detailedly as per working procedure，which includes structure design of ballastless track，bi-block prefabrication and production，equipment assembly and transitions，ballastless track control measurement，supporting layer construction，foundation construction，track bed slab concrete pouring，supporting foot installation and locatio.，and mechanical vibrating and embedding construction； the key points are emphatically explained concerning construction technology，resource allocation，labor force organization，and quality control，etc.The technical standard，design and construction method，technical key points and quality control measures mentioned in the book are gradually innovate.，enriched and improved in the construction of Zhengzhou-Xi’an passenger dedicated railway，and valuable experiences are also referred to and learned from the construction of CRTSⅠbi-block ballastless track in other high-speed railways.The book，as the important achievement of CRTSⅡbi-block ballastless track construction technology in China，represents the highest level in this field so far.

The chief editor of this book is Li Changning，associate editor is Dai Yu，and other participants in writing this book include Chang Yawen，Cao Dezhi，Lu Jianxin，Yang Hongwei，Xu Hong，Hou Xiaojun，Bai Yangjun，and Zhu Xiaoyi.We appreciate the guidance and strong support from Guo Fu’an，Gu Qiula.，and Liu Zengjie who are from the Engineering Management Center of China Railway.We also got the support from China Railway First Survey & Design Institute Group Co.，Ltd.，and China Railway No.3 Engineering Group Co.，Ltd.，many thanks to them all.

It must be noted that the expensive equipment applied for construction of CRTSⅡbi-block ballastless track in Zhengzhou-Xi’an passenger dedicated railway restricts its engineering application to some extent.Through constant exploration，research and innovation，Chinese engineering technical personnel present the frame track panel construction method，which has further enriched and improved the construction technology for CRTSⅡbi-block ballastless track，and made important contribution to the improvement of ballastless track technology.

There may still be some omissions and mistakes in this book，so valuable comments and suggestions from all readers are welcome for us to modify，supplement and improve in later edition.