|
|
|
| Unloading model test on open cut tunnels in high filled loess trench |
| MA Li1,LI Sheng2,WANG Qicai2,GENG Shaobo3,ZHANG Yanjie2,LI Jianxin2 |
(1. College of Civil Engineering,Lanzhou Institute of Technology,Lanzhou,Gansu 730050,China;
2. College of Civil Engineering,Lanzhou Jiaotong University,Lanzhou,Gansu 730070,China;
3. College of Civil Engineering,North University of China,Taiyuan,Shanxi 030051,China) |
|
|
|
|
Abstract In order to study the variation of vertical earth pressure and soil settlement of the open cut tunnel in high filled loess trench under different unloading measures,the unloading effect in different schemes were analyzed and compared through the indoor model test. The results show that increasing the angle of the filling slope,setting the low compacted soil on the top of the open cut tunnel,laying the geogrid and improving the compression modulus of filling on both sides of the open cut tunnel reduce the earth pressure on the top of open cut tunnel. The increase of slope angle has the best effect. The vertical earth pressure on the top of the open cut tunnel is reduced 20.6% in comparison with the one without the slope. The soil arch effect of low compacted soil and the effect of geogrid reduce further the vertical earth pressure on the top of the open cut tunnel. The vertical earth pressure is almost uniformly distributed when the height of earth filling is low. The vertical earth pressure decreases at first and then becomes stable as the increase of the filling height. The setting of low compacted soil resultes in a jump of the vertical earth pressure near the interface of virtual and compacted soil.
|
|
|
|
|
|
[1] LARSEN N G,HENDRICKSON J G. A practical method for construction rigid conduits under high fills[C]// Proceedings of the 41st Annual Meeting of the Highway Research Board. Washington,D. C.:[s. n.],1962:273–280.
[2] SLADEN J A,OSWELL J M. The induced trench method-a critical review and case history[J]. Canadian Geotechnical Journal,1988,25(3):541–549.
[3] 顾安全. 上埋式管道及洞室垂直土压力的研究[J]. 岩土工程学报,1981,3(1):3–15.(GU Anquan. Investigation of the vertical earth pressure on projecting conduit and underground chamber under a high embankment [J]. Chinese Journal of Geotechnical Engineering,1981,3(1):3–15.(in Chinese))
[4] 顾安全,郭婷婷,王兴平. 高填土涵洞(管)采用EPS板卸载的试验研究[J]. 岩土工程学报,2005,27(5):500–504.(GU Anquan,GUO Tingting,WANG Xingping. Experimental study on reducing-load measurement using EPS of culvert under high-stacked soil[J]. Chinese Journal of Geotechnical Engineering,2005,27(5):500–504.(in Chinese))
[5] 顾安全,吕镇锋,姜峰林,等. 高填土盖板涵EPS板卸载试验及设计方法[J]. 岩土工程学报,2009,31(10):1 481–1 486.(GU Anquan,LU Zhenfeng,JIANG Fenglin,et al. Load reduction tests and design methods for culverts with high fill soil using EPS slabs[J]. Chinese Journal of Geotechnical Engineering,2009,31(10):1 481– 1 486.(in Chinese))
[6] 郭婷婷,顾安全. 减荷措施下涵洞土压力与填土变形数值计算[J]. 交通运输工程学报,2010,10(5):12–17.(GUO Tingting,GU Anquan,Numerical simulation of soil pressure and deformation for culvert with load-reducing measures[J]. Journal of Traffic and Transportation Engineering,2010,10(5):12–17.(in Chinese))
[7] 曹周阳,王晓谋,王俊伟. 高填方双管涵洞减荷试验研究[J]. 工业建筑,2011,41(4):85–91.(CAO Zhouyang,WANG Xiaomou,WANG Junwei. Study on load reduction test for high-fill double pipe culvert[J]. Industial Construction,2011,41(4):85–91.(in Chinese))
[8] 马 强,郑俊杰,张 军,等. 高填涵洞卸载机制与数值分析[J]. 岩土力学,2010,31(增1):424–429.(MA Qiang,ZHENG Junjie,ZHANG Jun,et al. Mechanism analysis and numerical simulation on load reduction for culvert beneath high filling[J]. Rock and Soil Mechanics,2010,31(Supp.1):424–429.(in Chinese))
[9] 郑俊杰,马 强,张 军. 加筋卸载涵洞的涵顶土压力计算[J]. 岩土工程学报,2011,33(7):1 135–1 141.(ZHENG Junjie,MA Qiang,ZHANG Jun. Calculation of vertical earth pressure on load reduction culverts under embankments by reinforcement[J]. Chinese Journal of Geotechnical Engineering,2011,33(7):1 135–1 141.(in Chinese))
[10] 马 强. 高填涵洞受力特性及新型格栅卸载方法研究[博士学位论文][D]. 武汉:华中科技大学,2011.(MA Qiang. Study on stress characteristies and load reduction by triax geogrid reinforcement for high embankment culverts[Ph. D. Thesis][D]. Wuhan:Huazhong University,2011.(in Chinese))
[11] 杨锡武. 高填方涵洞土压力变化规律与影响因素的数值模拟研究[J]. 重庆交通学院学报,2004,24(5):42–48.(YANG Xiwu. Numerical simulation study on the law of earth pressures on the culvert beneath high embankment and the factors of effect on the earth pressures[J]. Journal of Chongqing Jiaotong University,2004,24(5):42–48.(in Chinese))
[12] 杨锡武,张永兴. 公路高填方涵洞土压力变化规律及计算方法研究[J]. 土木工程学报,2005,38(9):119–125.(YANG Xiwu,ZHANG Yongxing. Study on arch action and earth pressure theory for culverts under high embankment[J]. Chinese Journal of Rock Mechanics and Engineering,2005,38(9):119–125.(in Chinese))
[13] 杨锡武,张永兴. 山区公路高填方涵洞的成拱效应及土压力计算理论研究[J]. 岩石力学与工程学报,2005,24(21):3 887–3 893. (YANG Xiwu,ZHANG Yongxing. Study on arch action and earth pressure theory for culverts under high embankment[J]. Chinese Journal of Rock Mechanics and Engineering,2005,24(21):3 887– 3 893.(in Chinese))
[14] 杨锡武,张永兴. 山区公路高填涵洞加筋桥卸载方法及其设计理论研究[J]. 岩石力学与工程学报,2005,24(9):1 561–1 571.(YANG Xiwu,ZHANG Yongxing. Study on the method and theory of load reduction by reinforcement bridge for the culvert beneath high filling[J]. Chinese Journal of Rock Mechanics and Engineering,2005,24(9):1 561–1 571.(in Chinese))
[15] 李 盛,王起才,马 莉,等. 黄土地区高填土明洞土拱效应及土压力卸载计算[J]. 岩石力学与工程学报,2014,33(5):1 055–1 062. (LI Sheng,WANG Qicai,MA Li,et al. Earth pressure and soil arch effect for high fill open cut tunnel in loess area under different load reduction schemesy[J]. Chinese Journal of Rock Mechanics and Engineering,2014,33(5):1 055–1 062.(in Chinese))
[16] 李 盛,王起才,马 莉,等. 高填黄土明洞土拱效应及土压力卸载模型分析[J]. 土木工程学报,2014,47(7):118–125.(LI Sheng,WANG Qicai,MA Li,et al. Model analysis of earth pressure load reduction and soil arch effect for high fill open cut tunnel in loess area[J]. China Civil Engineering Journal,2014,47(7):118–125.(in Chinese)) |
|
|
|