滨海软基段公路管廊路基工后沉降特性研究

Post-construction Settlement Characteristics of Highway Pipe Gallery Roadbed in Coastal Soft Foundation Section

为了揭示软基段公路管廊路基工后的沉降特性,以滨海软基段某公路管廊路基为研究对象,利用FLAC3D有限差分软件分别对填土荷载作用下、不同管廊位置、不同路基高度下和土工格栅工况下的管廊路基的沉降特性进行分析。结果表明:荷载作用下,软基段既有管廊路基中,其沉降主要由施工期间路基填筑引起,管廊与周围土体差异沉降随着时间不断加剧,造成路面变坡率突变,与无管廊软土路基相比,将会扩大3倍左右;管廊位于路中、路肩、坡脚处对路基差异沉降的影响依次减小,当其位于坡脚时工后会产生3%左右的倾斜,对工程防水和变形缝设置提出了更高要求;土工格栅对于降低整体工后沉降具有一定的控制作用,但影响有限,在管廊路基中,减小的工后沉降量约占总体工后沉降的4%。

In order to reveal the post-construction settlement characteristics of the highway pipe gallery embankment in the soft foundation section,the subgrade of a highway pipe gallery in the coastal soft subgrade section is taken as an example,and the FLAC3 Dfinite difference software is used to analyze the fill load,different pipe gallery positions,different subgrade heights,and the settlement characteristics of the pipe gallery subgrade under the condition of the underground and geogrid.The results are as follows.Under the loading condition,the settlement of the existing pipe gallery subgrade in the soft foundation section is mainly caused by the filling of the subgrade during the construction period.The differential settlement of the pipe gallery and the surrounding soil has increased over time,resulting in a sudden change in the road slope rate.Compared with the soft soil roadbed without pipe gallery,it will be enlarged by about 3 times.The influence of the pipe gallery in the middle of the road,the shoulder and the toe of the differential settlement of the subgrade is reduced in turn.When it is located at the toe,it will have an 3%incline after construction,which poses a higher level of engineering waterproofing and deformation joints.The geogrid has certain control effects on the overall post-construction settlement,but the impact is limited.In the corridor roadbed,In the pipe gallery roadbed,the reduced post-construction settlement accounts for about 4%of the overall post-construction settlement.