海洋土取样应力释放三轴模拟试验研究

发布时间：2018-06-30 17:50

本文选题：海洋土 + 高压　；参考：《水文地质工程地质》2017年01期

【摘要】：基于海底现场取土样,利用GDS高压三轴试验仪重塑不同压力条件下的海洋土,在此基础上通过三轴加卸载试验,模拟研究高压海洋土在非保真取样过程中的卸荷响应特性,即围压-土样体积变化规律。饱和土样总体积变化一般可用反压体积变化近似描述,本文进一步考虑了高压水可压缩性的影响。通过不同加卸载循环次数以及卸载时间等的试验,表明其对高压试验结果影响很小,不同初始围压与孔压土样的卸荷试验则表明了孔压越大土样体积变化越明显等特点。卸载试验总的特征为:高压卸载过程中土样体积膨胀开始慢,发展逐渐变快,至尾段变化最快;不同作用因素对卸载中间阶段影响明显,而对初始段和末尾段影响不明显,这与中低压卸载特性存在一定区别。
[Abstract]:Based on the soil samples taken from the seabed field and the GDS high pressure triaxial test instrument, the unloading response characteristics of the high-pressure marine soil in the process of non-fidelity sampling were simulated by triaxial loading and unloading tests. That is, confining pressure-soil sample volume change law. The change of total volume of saturated soil can be approximately described by the change of backpressure volume. The effect of compressibility of high pressure water is further considered in this paper. Through the tests of different loading and unloading cycles and unloading time, it is shown that it has little influence on the high pressure test results, and the unloading tests of different initial confining pressures and pore pressure soil samples show that the larger the pore pressure is, the more obvious the change of soil sample volume is. The general characteristics of unloading tests are as follows: the volume expansion of soil samples begins to slow and develops faster during unloading under high pressure, and the change is the fastest at the end, the effect of different factors on the middle stage of unloading is obvious, but the effect on the initial stage and the end segment is not obvious. This is different from the characteristics of medium and low pressure unloading.
【作者单位】：宁波工程学院;伦敦南岸大学;中国科学院武汉岩土力学研究所/岩土力学与工程国家重点实验室;
【基金】：浙江省自然科学基金项目资助(LY13E080009)
【分类号】：TU411

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