【摘要】：基于目前研究很少關(guān)注土拱效應(yīng)模型的適用條件和演化規(guī)律的現(xiàn)狀,采用自制平面應(yīng)變模型對砂填料樁承式路堤在不同樁間距下的宏觀土拱形態(tài),以及宏觀土拱在樁間土下移過程中可能出現(xiàn)的演化現(xiàn)象進(jìn)行探討。模型試驗將樁與土相互作用簡化為樁間土擋板下移這一位移邊界條件,配備可精確控制樁間土下移量的位移控制裝置與攝影測量設(shè)備。每下移0.02 mm采集一張圖片,采用圖像分析軟件追蹤樁間土下移過程中路堤顆粒位移,實(shí)現(xiàn)全場位移量測。共進(jìn)行3種填土高度下3種不同樁間距的模型試驗。通過對9組試驗填料內(nèi)部滑移面的分析,揭示樁間土下移過程中均首先出現(xiàn)對稱的三角形滑移面,即初始三角拱模型,之后繼續(xù)增加樁間土下移量,初始三角拱模型存在2種不同的演化模式:在填土高度與樁距比1.8情況下,隨樁間土下移量的增加滑移面逐級張開,稱為三角多拱模型;在填土高度與樁距比≥1.8情況下,滑移面則逐級上移,演化為塔形多拱模型。最后,統(tǒng)計各模型的關(guān)鍵參數(shù),為下一步土拱演化條件下的力學(xué)分析計算提供依據(jù)。
[Abstract]:Based on the fact that little attention has been paid to the applicable conditions and evolution rules of the soil arch effect model at present, the self-made plane strain model is used to study the macroscopic soil arch shape of the sand filled pile supported embankment under different pile spacing. The evolution of macro-soil arch in the process of soil displacement between piles is discussed. The pile-soil interaction is simplified as the displacement boundary condition of soil retaining plate in the model test, and the displacement control device and photogrammetric equipment can accurately control the soil displacement between piles. One image was collected with 0.02 mm downward, and the displacement of embankment particles was tracked by image analysis software in the process of soil movement between piles, and the displacement measurement of the whole field was realized. The model tests of three different pile spacing under three different fill heights were carried out. Based on the analysis of the slip surface in 9 groups of test fillers, it is revealed that the symmetrical triangular slip plane is first appeared in the soil movement between piles, that is, the initial triangular arch model, and then the amount of soil sliding between piles continues to increase. There are two different evolution models in the initial triangular arch model: when the ratio of fill height to pile distance is 1.8, the slip surface is opened step by step with the increase of soil displacement between piles, which is called triangle multi-arch model, and when the ratio of fill height to pile distance is 鈮，

本文編號：2169756