张志龙, 王红雨. 2023. 饱和欠固结土竖井地基固结分析——以坝前淤积土为例[J]. 工程地质学报, 31(6): 2093-2103. doi: 10.13544/j.cnki.jeg.2021-0583.
    引用本文: 张志龙, 王红雨. 2023. 饱和欠固结土竖井地基固结分析——以坝前淤积土为例[J]. 工程地质学报, 31(6): 2093-2103. doi: 10.13544/j.cnki.jeg.2021-0583.
    Zhang Zhilong, Wang Hongyu. 2023. Consolidation behavior of saturated under-consolidated foundation with vertical drains: Example from upstream sediment in front of dam[J]. Journal of Engineering Geology, 31(6): 2093-2103. doi: 10.13544/j.cnki.jeg.2021-0583.
    Citation: Zhang Zhilong, Wang Hongyu. 2023. Consolidation behavior of saturated under-consolidated foundation with vertical drains: Example from upstream sediment in front of dam[J]. Journal of Engineering Geology, 31(6): 2093-2103. doi: 10.13544/j.cnki.jeg.2021-0583.

    饱和欠固结土竖井地基固结分析——以坝前淤积土为例

    CONSOLIDATION BEHAVIOR OF SATURATED UNDER-CONSOLIDATED FOUNDATION WITH VERTICAL DRAINS: EXAMPLE FROM UPSTREAM SEDIMENT IN FRONT OF DAM

    • 摘要: 淤地坝在黄河中上游水土流失治理中发挥着重要作用,而“坝前淤积面加坝”是除险加固病险淤地坝常用的一种施工方法。针对饱和欠固结状态的坝前淤积土大变形非线性计算问题,文中采用分段线性方法构建了饱和欠固结土竖井地基固结模型(RSUC)并编写了Fortran计算程序。在验证新建模型准确性的基础上,对比分析了欠固结土与正常固结土竖井地基固结计算结果的差异。通过工程案例分析了淤积土的自重固结过程,讨论了增设塑料排水板对淤积土堆载固结的影响。结果表明,计入欠固结土前期未消散的超静孔隙水压力,使得欠固结土竖井地基的固结速度比正常固结竖井地基慢;欠固结淤积土在晾晒期间其体内孔隙比、超静孔压随深度呈非线性变化,底部固结速度、沉降值相对较大;布设塑料排水板可以减缓堆载引起的淤积土坝基中超静孔隙水压力的峰值,加速淤积土的固结速度、减小工后沉降,增加坝基的稳定性。

       

      Abstract: Warping dams play an important role in the control of soil and water loss in the upper and middle reaches of the Yellow River, and "upstream sediment heightening fill" is a common construction method in the check dams reinforcement engineering. Aiming at the calculation problem of the sediment in front of the dam in a saturated and under-consolidated state, the radial large-strain under-consolidated settlement model(RSUC) of the silted foundation with prefabricated vertical drains(PVDs) is established using the piecewise linear method. The paper verifies the accuracy of the RSUC model, compares the different consolidation behaviors between under-consolidated and normally consolidated foundation with PVDs. Through engineering cases, the self-weight consolidation process of sediment is analyzed, and the influence of adding PVDs on the consolidation of sediment is discussed. The results show that the undissipated excess pore water pressure before constructing makes the consolidation speed of the under-consolidated sediment foundation slower than that of normally consolidated sediment foundation with PVDs. The void ratio and excess pore water pressure of the under-consolidated sediment during the drying period show non-linear changes with the relative elevation. The bottom consolidation speed and settlement value are relatively large. Apart from accelerating the consolidation speed of sediment and reducing post-construction settlement, installing the PVDs for silted foundation can reduce the maximum value of excess pore water pressure in the sediment and increase the stability of the dam foundation.

       

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