文档介绍：本科学生毕业论文
论文题目:
冻融循环作用下素土静力学特性研究
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摘要
黑龙江省地处我国最北端高纬度区,区内深季节冻土(冻结深度>1m)分布广泛,冬冻春融的冻融循环作用引起的路基冻害问题。在冻土地区进行工程建设,就必须深入研究冻土的力学特性,以确保冻土地基上工程建筑物的稳定性。本文首先,简要介绍了我国冻土的分布状况、冻土的物理力学性质及其对工程的影响和国内外研究现状。
由于冻融作用的存在,道路会发生翻浆、路基冻胀或不均匀冻胀、和路基融沉的现象,伴随季冻区内温度的降低,个别寒区道路由于冻胀灾害严重,致使道路鼓包,而阻碍行车安全,在春季消融阶段,冻结的路基土层融化,但不同位置的土层融化时间不尽相同,造成翻浆破坏,是长期困扰该地区公路建设的一个突出问题。因此在冻土地区进行工程建设,必须深入研究冻土的力学特性,以确保冻土地基上工程建筑物的稳定性。
针对黑龙江省季节冻土在冻融循环条件下的主要物理力学性质,进行土样基本性质测试和力学试验研究。试验结果表明:试样经历 6次冻融后,其含水量、干密度、黏聚力、内摩擦角等物理力学性质趋于稳定。土体冻融最终平衡状态与初始状态相关,其中初始干密度的影响尤为重要。随冻融循环过程增加,土体的黏聚力下降,内摩擦角变化较小。
所以冻融作用对素土的物理力学性质有明显影响,在春融期的不利季节,素土含水量大处于不稳定状态,是造成季冻区道路破损的主要原因,研究结果可为季冻区道路设计提供技术参数,为养护管理决策提供技术支持,对提高季冻区道路建设质量具有积极意义。
关键词
冻土;力学性质;冻融作用;研究现状
Abstract
Heilongjiang province is located in China's northernmost high latitude area, zone of deep seasonal frozen soil (frozen depth of > 1 m) are widely distributed, winter cold melting in the spring of the freeze-thaw cycle effect caused by subgrade frost damage problem. For engineering construction in permafrost regions, it is necessary to in-depth study the mechanical properties of frozen soil, to ensure that the frozen soil foundation on the stability of engineering building. In this paper, first of all, the distribution of the permafrost in China are briefly introduced, the physical and mechanical properties of frozen soil and influence on engineering and research status at home and abroad.
Pumping will happen due to the existence of the freeze-thaw action, road, roadbed uneven frost heaving and frost heave, and the phenomenon of subgrade thawing settlement, with season of freezing zone temperature, cold and individual road due to frost heaving disaster is serious, the road to bulge, and hinder the driving safety, stage of melting in the spring, frozen subgrade soil melt, but different location of soil thawing time is not the same, pumping damage, long plagued the region highway construction is an outstanding problem. For engineering construction in permafro