摘要
为研究泡沫轻质土用作软基上路基拓宽填料时的应力应变规律,对不同填筑高度(3 m,5 m,8 m,10 m,15 m)和拓宽宽度(4.5 m,5.75 m,8.25 m,9.5 m,12 m)的路基拓宽情况运用有限元软件进行了模拟分析;以唐津高速扩建工程试验段为依托工程,分析试验结果,结合理论分析得到结论:(1)固定填高5 m,在轻质土浇筑完成时,拓宽路基基底沉降分布较均匀。随拓宽宽度增大,从距路中心15 m处开始,沉降曲线曲率明显变大,最大沉降值由3.80 cm逐渐增加到8.61 cm;拓宽路基基底附加应力随拓宽宽度的增加而增大,基底应力分布较均匀,基本为中部小、两侧大。但拓宽4.5 m和5.75 m时附加应力变化起伏较大,拓宽8.25 m,9.5 m和12 m时较平滑;当包边土及路面结构填筑完成后,地表各处沉降值显著增长,最大值达15.88 cm。各拓宽宽度下,沉降最大值明显右移,内侧基底应力明显小于外侧应力,出现右侧偏心现象。(2)固定拓宽宽度8.25m,在轻质土浇筑完成时,各处沉降值随填高增高而增加。但新旧路基基底沉降差值不大,均不足3 cm;拓宽路基基底附加应力随填筑高度增加而增大,呈两侧应力大,中部小而均匀的形式分布。在填高3 m和5 m时,路基基底内角点与右侧应力差均在15 k Pa左右,出现显著的左侧偏心现象;当包边土及路面结构填筑完成后,沉降值与沉降差随填高增大而增加,填高为15 m时,最大沉降量超过20.36 cm,沉降差达10 cm;路基基底左侧应力明显小于右侧应力,右侧偏心现象明显。但填高为15 m时,应力集中在55.5 k Pa左右,偏心现象不明显。
In order to study the stress-strain relationship of foamed lightweight soil in widening of freeway on soft soil foundation,different filling height（ 3 m,5 m,8 m,10 m,15 m） and width（ 4. 5 m,5. 75 m,8. 25 m,9. 5 m,12 m） of roadbed cases were analyzed using finite element soft-ware. Combining the test results from the reconstruction of Tang-Jin Freeway,the analysis results can be summarized as follows. If the fill height is 5 m and the pouring of lightweight soil has been completed,the distribution of basement subsidence is relatively uniform. With the increase of widening width,the curvature of settlement curve becomes large from the center of the road at 15 m,and the value of maximum settlement gradually increases from 3. 80 cm to 8. 61 cm. The additional base stress of the widening subgrade increases with the increase of widening width,the additional base stress distribution of the widening subgrade is relatively uniform,and the stress in the middle is smaller than that on the left and right sides. The additional base stress fluctuation with the widening width of 4. 5 m or 5. 75 m is larger than that with the widening width of 8. 25 m,9. 5 m and 12 m.When the wrapping soil and pavement structure filling is finished,the sedimentation increases significantly,and the maximum value reaches 15. 88 cm. The maximum settlement of each widening width obviously shifts to the right. Besides,the inside base stress of each widening width is obviously less than that of the outside,and the eccentric phenomenon appears on the right. If the widening width is 8. 25 m and the pouring of light soil has been completed,the settlement increases with the increase of filling height. However,the settlement difference between the old and new subgrade is less than 3 cm. The additional base stress increases with the increase of filling height,and the additional base stress in the middle is smaller than that on the left and right sides. When the filling height is 3 m or 5 m,the difference between the stress at interior corner point of subgrade and the stress on the right side is about 15 k Pa,and the eccentric significant phenomenon appears on the left. When the wrapping soil and pavement structure filling is finished,the settlement value and settlement value difference increase with the increase of filling height. When the filling height is 15 m,the maximum settlement reaches 20. 36 cm,and the maximum settlement difference is 10 cm. The stress value of the left subgrade is significantly smaller than that of the right side,and the right eccentric phenomenon is obvious. However,when the filling height is 15 m,the stress concentrates at55. 5 k Pa,and then the eccentric phenomenon is not obvious.
出处
《广西大学学报（自然科学版）》
CAS
北大核心
2016年第1期234-245,共12页
Journal of Guangxi University（Natural Science Edition）
基金
河北省自然科学基金项目(E2012202161)
天津市市政公路局科技计划项目(2013-03)
关键词
道路工程
路基拓宽
软基
泡沫轻质土
应力应变
数值模拟
road engineering
widening subgrade
soft soil foundation
foamed lightweight soil
stress-strain
numerical simulation
