水质对固化土性能的影响

发布时间：2018-02-02 12:36

本文关键词： MBER土壤固化剂 NaCl 有限元分析　出处：《西北农林科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：MBER固化土已经在黄土高原得到了广泛应用,但是在海水咸水地区、盐渍土地区的应用研究还是空白。针对这一问题,本文通过试验、计算软件研究分析了水质对固化土性能的影响,得到以下研究结果:(1)水质对固化土抗压强度影响试验研究针对MBER固化剂在咸水地区应用研究空白,采用不同浓度的氯化钠溶液,对MBER固化土的无侧限抗压强度和弹性模量的规律性进行了试验研究。根据试验结果,获得了MBER固化土的7d与28d无侧限抗压强度的函数关系,水的含盐度对固化土应力应变-关系的影响,弹性模量与抗压强度的关系曲线,随着氯化钠浓度增加,当氯化钠浓度低于0.5%时,无侧限抗压强度及弹性模量增加;氯化钠浓度高于0.5%时,无侧限抗压强度及弹性模量降低;弹性模量与无侧限抗压强度随含盐度变化的趋势基本一致,两者存在较好的线性相关性;适量浓度氯化钠溶液对固化土早期强度提升显著。研究得出,实际工程中水的氯化钠浓度低于1%时,可应用于固化土工程建设。(2)水质对固化土劈裂抗拉强度影响实验研究为研究水质对劈裂抗拉强度的影响,采用不同浓度的氯化钠溶液,对MBER固化土的劈裂抗拉强度的规律性进行了试验研究。获得了含盐水质影响条件下,固化土的劈裂抗拉强度随水的氯化钠浓度变化的关系以及劈裂抗拉强度与无侧限抗压强度的关系,根据试验结果,7d劈裂强度受氯化钠浓度影响相对于28d明显,其强度随着氯化钠浓度增加而减小,而28d劈裂强度受氯化钠浓度影响不明显。总的来看,固化土劈裂抗拉强度随氯化钠浓度的增加没有明显变化,基本维持水平。说明氯化钠对固化土劈裂强度的影响随着养护时间的增加而逐渐减小。(3)水质对海泥性能影响试验研究为研究水质对海泥性能影响,采用不同浓度的氯化钠溶液,对MBER加固海泥的劈裂抗拉强度的规律性进行了试验研究。试验结果表明,盐分对海泥强度影响变化趋势不明显。(4)固化土道路结构分析及水质对其性能的影响通过对固化土道路结构分析,发现,在车辆荷载作用下最大拉应力发生在固化土面层的底部,而最大压应力发生在固化土面层顶部轮胎作用处;路面应力主要集中在车辆轮胎作用处附近,在模型中远离轮胎荷载的大部分位置的受的应力较小,与轮胎荷载附近的应力相差三个数量级。B、盐渍土地区的固化土道路,以延安安塞地区为例,当含盐度低于阀值时,可以适当较小固化土路面厚度达到较好的经济效益;当含盐度高于阀值时,此时修建的固化土道路应在饮用水拌合固化土修建固化土道路的基础上加大固化土面层的厚度,以保证工程安全可靠。(5)水窖有限元分析为研究水质对固化土工程构件的影响,利用有限元分析方法对固化土干性水窖在满窖和空窖两种不利工况下的应力进行了分析,得出空窖工况下固化土水窖受到的最大拉应力与最大压应力大于满窖工况下的应力,即相对于满窖工况空窖工况为不利工况。分析了水质对固化土水窖性能的影响。当水的含盐度从0—4.5%变化时,根据室内实验数据,利用ANSYS分析最不利条件即空窖条件下的水窖的受力和变形,发现随着水质含盐度的增加,水窖所受的应力没有变化,应变先减小后增加,在含盐度为0.5%是,应变最小,而水窖的应力没有变化。
[Abstract]:MBER solidified soil has been widely used in the Loess Plateau, but in the sea water area, saline land area application research is still blank. To solve this problem, through the test, calculation software research and analysis of the influence of water quality on the performance of solidified soil, the results are as follows: (1) the water quality of solidified soil compressive strength experimental study on MBER curing agent in the salt water area application blank, with different concentrations of MBER on Sodium Chloride Solution, the solidified soil showed no regularity of compressive strength and elastic modulus were studied. According to the test results, obtained the 7d and 28d of MBER solidified soil is not a function of unconfined compressive strength, water the salinity stress strain relationship of solidified soil, the relationship curves of elastic modulus and compressive strength, with the increase of the concentration of sodium chloride, when sodium chloride concentration is lower than 0.5%, the unconfined compressive strength The increase of elastic modulus; sodium chloride concentration is higher than 0.5%, no decrease of unconfined compressive strength and elastic modulus; elastic modulus and unconfined compressive strength with the salinity change tendency is consistent, there is a good linear correlation between the amount of solid concentration; Sodium Chloride Solution soil early strength were significantly improved. The sodium chloride the actual engineering water concentration is lower than 1%, which can be applied to the solidified soil engineering construction. (2) the water quality of solidified soil splitting tensile strength experimental study on the effect in order to study the effect of water quality on the splitting tensile strength, with different concentration of Sodium Chloride Solution, regularity of the splitting tensile strength of MBER stabilized soil tested study on salt water quality impact. The relationship between the changes of conditions, splitting tensile strength increases with the concentration of sodium chloride in water of solidified soil and the splitting tensile strength and the relationship between unconfined compressive strength and root According to the test results, 7d splitting strength is affected by the concentration of sodium chloride was compared with 28d, its strength decreases with the increase of NaCl concentration, while 28d splitting strength affected by the concentration of sodium chloride is not obvious. In general, splitting tensile strength of solidified soil increases with the concentration of sodium chloride did not change significantly, to maintain the basic level. Effect of sodium chloride on the splitting strength of the solidified soil with the increase of curing time decreased gradually. (3) the water quality of the mud performance experimental research on the effect in order to study the effect of water quality on the performance of mud, with different concentrations of Sodium Chloride Solution, the law of the splitting tensile strength of MBER reinforced mud was studied. The experimental results show that the change trend of effect of salinity on mud strength is not obvious. (4) impact analysis and water stabilized soil road structure on the performance of the solidified soil road structure analysis, found in the vehicle load Under the maximum tensile stress occurs in the solidified soil surface layer at the bottom, while the maximum compressive stress occurs in the soil surface layer at the top of the tire curing effect; pavement stress is mainly concentrated in the vicinity of vehicle tire, most position away from the tire load in the model of stress is smaller, and the tire load nearby the stress difference of three orders of magnitude.B, solidified soil road in saline soil area, taking Yanan Ansai area as an example, when the salinity is lower than a threshold, can be less stabilized soil pavement thickness to achieve better economic benefits; when the salinity is higher than the threshold value, the construction of the road should be solidified soil foundation construction of solidified soil in road drinking water mixing on the solidified soil solidified soil to increase the thickness of the surface, to ensure the safety and reliability of the project. (5) finite element analysis for the effect of water quality on soil solidification engineering components, of solidified soil by finite element method Dry cellar in full and empty cellar cellar of two kinds of stress under adverse conditions are analyzed, the maximum tensile solidified soil under the condition of empty cellar cellar by stress and maximum compressive stress is greater than the stress under the condition of full pit, which is relative to the full working condition of empty cellar pit water analysis of the impact of adverse conditions. Quality of solidified soil cellar performance. When the water salinity changes from 0 - 4.5%, according to the experimental data, using the ANSYS analysis of the most unfavorable conditions that empty cellar under the condition of water stress and deformation, it is found that with the increase of water salinity, water stress did not change, the first strain increased and then decreased, with a salinity of 0.5%, the minimum strain, and the water stress did not change.

【学位授予单位】：西北农林科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU43

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