|
|
|
| Exploration on the Compaction Mfect of Static Pressure in Foundation of Loess Tunnel of Baoji - Lanzhou Passenger Dedicated Line |
| MI Wei - jun1, JIA Yun2, JIA Yan3, QU Yao - hui1 |
| (1. Northwest Research Institute Co. Ltd of CREC, Lanzhou, Gansu 730000, China; 2. Lanzhou LS Group Co. Ltd , Lanzhou , Gansu 730050 , China; 3. Lanzhou Railway Survey and Design Institute Co. Ltd , Lanzhou , Gansu 730000 , China) |
|
|
|
Abstract Research purposes ： There are five geomorphic units and lots of loess along Baoji - Lanzhou passenger dedicated line, with the characteristic of high collapse grade and large vulnerability of vibration with big thickness. But there are high standard and difficult vibrate - controlling about treatment of loess tunnel foundation. The geomorphic unit of Anjiazhuang loess tunnel is loess plateau and mountain ridge area , the loess around tunnel is provided with strong collapsibility , and collapsible grade of area is IV ( very serious) , besides , the dark cave foundation uses the design of piles of preformed holes which are made by static pressure.
Research conclusions: The results showed that:(1) The treatment method and equipment about static pressure , which was developed by Northwest Research Institute Co. Ltd of China Railway Engineering Corportion, suit to compaction of foundation in loess tunnel. (2) If the goal is to eliminate the collapsibility of loess between piles and make the compaction coefficient meet the specification, the suitable pile diameter and spacing hade are 0. 41 m and 0. 91 m respectively. (3) If the bearing capacity meets design requirement, the minimum coefficient of compaction and the average coefficient of compaction can be less than the specified standard , and the suitable pile diameter and spacing hade are 0. 41 m and 1.2 m respectively. (4) The research results can be directly applied to design and construct about the compaction treatment of tunnel foundation in collapsible loess, also can be used to reinforce and process foundation at collapsible loess site with narow and small space and non - vibration space.
|
|
Received: 20 July 2015
|
|
|
|
|
|
|
2015, Vol. 32 
