黄土化学改良试验研究

EXPERIMENTAL RESEARCH ON CHEMICAL IMPROVEMENT OF LOESS

黄土的化学改良是黄土工程地基处理研究领域中的重要课题之一,开展这方面的研究对于治理黄土地基基础工程,从根本上解决黄土危害具有重要的理论价值和较好的工程应用前景。在我国西北、华北地区,经常要碰到填筑路基、渠道和边坡等黄土工程,由于黄土及重塑黄土具有许多特殊的物理力学性能,必须经过改良处理后才可应用。为了探讨化学材料对黄土特性的影响,本文以山西太原黄土为对象,通过掺加新型高分子土固化材料SH和水泥进行化学改良,就改良土试样进行抗压强度、直接剪切和渗透试验等分析研究。研究结果表明:SH和水泥均能改变黄土的工程性质。黄土加固后强度指标,抗渗性优于黄土本身。固化黄土的强度特性和渗透性能受固化材料掺量、密度和龄期的影响明显。随着掺量增加,密度增大和养护时间的延长,抗压强度提高,抗剪强度增强,渗透系数减小。考虑到大掺量会超过经济限度,建议两者较适宜掺量控制在10%左右。SH为水溶性液体固化材料,固含量较少,成本较低,但固化后强度较大,渗透性小,浸水不崩解,化学改良效果优于水泥,实际应用时可根据具体情况考虑优先选用SH改良黄土。

Chemical improvement of loess is an important topic in the area of loess foundation engineering treat- ment. It has important theoretical value and good applied prospects in loess foundation treatment, loess hazard and control. Loess as filling material of roadbed, channel and slope engineering is frequently encountered in northwest and north of China. Loess and remolded loess possess many distinctive physical-mechanical properties that can lead to the improvement and development of various ground improvement techniques such as soil solidification and rein- forcement. Loess must be improved. Otherwise it cannot be applied to engineering construction. In order to study the effects of loess solidified by chemical materials, a series of indoor experiments are conducted to analyze the properties of the raw loess of Taiyuan before and after treated by mixed with varying contents of new polymer-soil stabilizer（SH） and cement. The results of compressive strength, direct shear and permeability tests show that the engineering properties of the loess are improved by SH or cement. The strength and impermeability of solidified lo- ess with chemical solidified materials are better than the raw loess. The properties of strength increased with the content of solidified agent, its density and curing time, but the permeability coefficients decreased. The suitablecontent of mixed SH or cement is about 10%. SH is a new polymer-stabilized agent of water-solubility its less cement dosage, cheap price, high strength, low permeability and no disintegrating effect on loess, SH is SH can be taken into consideration according to practical situation. Because of better thancement. SH can be taken into consideration according to practical situation.