搅拌桩用工业废料胶结剂的实验室研究

对比了工业废料胶结剂加固土与425普通硅酸盐水泥加固土的无侧限抗压强度试验、压缩固结试验和渗透试验的结果,以验证工业废料胶结剂代替普通水泥的可行性．同时,对无侧限抗压强度的影响因素进行了分析,并给出了相应的关系表达式。     

粉煤灰炉渣加固土的室内无侧限抗压强度试验研究(英文)

给出了用粉煤灰、炉渣等工业废料加固土的室内无侧限抗压强度试验结果,分析了加固土无侧限抗压强度与外加剂掺量、养护龄期之间的影响规律,得出了针对不同工业废料加固土所用外加剂的最佳掺量。     

工业废料胶结剂加固土与普遍水泥加固土的对比试验研究

工业废料胶结剂是指一种利用工业废料加工而成的用于深层搅拌的新型土体胶结剂,本文主要讨论并对比了工业废料胶结剂加固土与４２５号普通硅酸盐水泥土的无侧限抗压强度试验,以验证工业废料胶结剂代替普通水泥的可行性。同时,对无侧限抗压强度的影响因素进行了分析,并给出了相应的关系表达式。     

工业废料胶结剂加固土与普通水泥加固土的对比试验研究

工业废料胶结剂是指一种利用工业废料加工而成的用于深层搅拌桩的新型土体胶结剂.本文主要讨论并对比了工业废料胶结剂加固土与425号普通硅酸盐水泥土的无侧限抗压强度试验,以验证工业废料胶结剂代替普通水泥的可行性.同时,对无侧限抗压强度的影响因素进行了分析,并给出了相应的关系表达式.     

不同土性对加固土加固性能带来的影响

本文通过试验讨论了上海地区三种典型的土质对加固土的不同影响。从重度试验和无侧限抗压强度试验着手,总结出不同土性下加固土 重度和无侧限抗压强度的变化规律,并且为采用搅拌桩及类似方法的复合地基提供了更可靠的理论依据。文中 还对比 了工业废料加固土和425^# 普硅水泥加固土受土性影响的差异。     

不同土性对加固土加固性能的影响

本文通过试验讨论了上海地区三种典型的土质对加固土的不同影响.从重度测试和无侧限抗压强度试验着手,总结出不同土性下加固土重度和无侧限抗压强度的变化规律,并且为采用搅拌桩及类似方法的复合地基提供了更可靠的理论依据.文中还对比了工业废料加固土和425#普硅水泥加固土受土性影响的差异.     

掺加工业废料加固土的试验研究

介绍了一种新型加固土。从水泥土固化机理出发,讨论并对比了掺加工业废料加固土与普通水泥土的无侧限抗压强度试验。     

粉喷桩固化剂新型材料试验与分析

介绍一种新型材料与水泥的混合物作为粉喷桩固化剂的混合料加固土，讨论了加固土的无侧限抗压强度、抗拉强度和变形模量的试验结果和它们之间的相互关系以及影响加固土强度的主要因素。     

水泥加固酸污染土无侧限强度特征

污染土是利用水泥固化处理后,土体的强度得到提高。针对该项技术,采用水泥固化法处理酸污染土,通过两种试验方案,对水泥加固酸污染土的无侧限抗压强度特性进行研究。试验所用酸污染土用浓硫酸配置人工制备而成,并考虑了不同水泥掺量、不同硫酸浓度和不同龄期对水泥加固酸污染土强度的影响。试验表明:水泥固化酸污染土的强度与水泥掺量和硫酸含量有密切关系,二者共同作用决定其强度的变化。在一定硫酸浓度(2~16g/kg)条件下,伴随硫酸含量的升高,水泥掺量较低时,无侧限抗压强度整体呈明显下降的趋势;水泥掺量较高时,无侧限抗压强度呈缓慢上升的趋势。随着水泥掺量提高,土样的无侧限抗压强度达到峰值时所对应的硫酸含量也逐渐变大。     

基于水灰比准则的水泥土无侧限抗压强度预测

现行规范对于水泥加固土无侧限抗压强度预测方法不明确,通过引用D.Abrams提出的混凝土水灰比理论,修正了水泥固化高含水率疏浚泥无侧限抗压强度预测方法,为减少室内试验量和缩短工期提供了依据。     

Compressive strength of fiber reinforced highly compressible clay

Admixtures and geogrids are frequently used in practice to stabilize soils and to improve their load carrying capacity. In this study, polyester fibers were mixed with soft clay soil to investigate the relative strength gain in terms of unconfined compression. Samples were tested in unconfined compression with 0%, 0.5%, 1.0%, 1.5% and 2.0% plain and crimped polyester fibers. Verifications tests were also performed to investigate the repeatability of the test results. The results presented show that the degree of compaction affected the relative benefits of fiber reinforcement for the subject soil. Samples compacted after mixing various proportions of sand into clay (varying from 0% to 12% of clay) were also tested. It was observed that unconfined compressive strength of clay increases with the addition of fibers and it further increases when fibers are mixed in clay sand mixture. Verification tests performed revealed that even though the fibers were randomly oriented, tests results can be reproduced with reasonable accuracy.     

灵敏性粉土的压缩及触变特性研究

山西汾河一级阶地的饱和粉土大多具有灵敏性,使得其强度和变形性质在扰动前后差别很大.为了研究灵敏性粉土的压缩及触变特性,对探井取样的原状土和重塑土样进行了一维固结压缩试验和无侧限抗压强度试验.试验结果表明,原状土加载到结构屈服应力处,沉降量突增,固结系数突增,主固结比突降,次固结对沉降的贡献开始上升;原状土与重塑土的差异...     

SPB和SPC固化稳定化镍锌污染土的强度及环境特性研究

以某汽配厂搬迁遗留电镀车间的镍(Ni)、锌(Zn)复合污染土为研究对象,研究2种新型固化剂SPB和SPC固化稳定化污染土的强度及环境安全特性。通过室内试验研究2种固化剂修复污染土的无侧限抗压强度(qu)、干密度(rd)、酸碱度(pH)、酸缓冲能力(ANC)及重金属浸出毒性、重金属形态分布等参数随固化剂掺量和养护龄期的变化规律。室内试验结果表明,污染土经固化剂SPB和SPC处理后q_u和rd显著提高,相同固化剂掺量、反应稳定(28 d)后,SPC固化土qu略高于SPB固化土,2种固化土rd基本相同;固化剂SPB和SPC使活性形态重金属转化为较稳定形态,重金属浸出浓度显著降低,但2种固化剂对重金属的固化稳定化效果存在差异,固化剂SPC固化稳定化Ni的效果优于固化剂SPB,而固化剂SPB固化稳定化Zn的效果更优;固化土pH显著提高,其中固化剂掺量10%、反应稳定后,SPB和SPC固化土pH分别为9.51和9.07;SPB和SPC固化土ANC均显著提高。另外,小试试验结果表明,SPC固化土pH低于PC固化土;固化剂SPC在短期养护(7 d)的固化效果优于PC。研究结果可以为固化剂SPB和SPC在实际工程的现场应用提供参考和建议。     

团聚体大小对填筑土强度影响的试验研究

为了了解团聚体大小对填筑土强度的影响,对不同改性填筑土的12组土样进行了一系列的无侧限抗压和剪切试验。结果表明:当团聚体的平均粒径小于3.5mm时,素土、纤维土和石灰土的粘聚力随粒径的增大而减小,内摩擦角随粒径的增大而增大;当团聚体的平均粒径大于3.5mm时,随粒径的增大,素土和石灰土的粘聚力明显增大且内摩擦角明显减小,纤维土的粘聚力和内摩擦角则变化不大;在受压破坏时,素土表现为应变软化的塑性破坏,纤维土表现为应变硬化的塑性破坏,石灰土则表现为完全的脆性破坏;素土、纤维土和石灰土的无侧限抗压强度随团聚体粒径的增大而降低。在试验结果的基础上,对团聚体大小的影响机理进行了分析和讨论。试验结论对进一步认识和掌握填筑土的工程性质具有重要意义。     

Mechanical behavior of lightweight soil reinforced with waste fishing net

Lightweight soil is cement-treated and consists of dredged clayey soil, cement, and air-foam. Reinforced lightweight soil (RLS) contains waste fishing net to increase its shear strength. This paper investigates the strength characteristics and stress–strain behavior of reinforced and unreinforced lightweight soils. Test specimens were prepared with varying admixtures of cement content (8%, 12%, 16%, and 20% by the weight of untreated soil), initial water content (125%, 156%, 187%, 217%, and 250%), air-foam content (1%, 2%, 3%, 4%, and 5%), and waste fishing net (0%, 0.25%, 0.5%, 0.75%, and 1%). Then several series of unconfined compression tests and one-dimensional compression tests were conducted. The experiments with lightweight soil indicated that the unconfined compressive strength increased with an increase in cement content, but decreased with increasing water content and air-foam content. The stress–strain relationship and the unconfined compressive strength were influenced by the percentage of waste fishing net. In addition, the strength of RLS generally increased after adding waste fishing net due to the bond strength and the friction at the interface between waste fishing net and soil mixtures, but the amount of increase in compressive strength was not directly proportional to the percentage of waste fishing net. The results of testing indicated that the maximum increase in compressive strength was obtained for a waste fishing net content of about 0.25%. The bulk unit weight of lightweight soil was strongly dependent on the air-foam content. The compression characteristics of lightweight soil, including the yield stress and compression index, did not depend greatly on whether the samples were cured underwater or in air.     

上海水泥固化黏土的强度与硬度相关性研究

现场施工过程中,往往需要对水泥固化土的无侧限抗压强度进行快速检测。针对目前水泥固化黏土无侧限抗压强度检测中存在的操作不简便、试验时间长、测试费用高等缺点,提出通过水泥土硬度估计强度的方法,对现场水泥土强度进行快速检测。本文以上海地区黏性土为研究对象,对上海地区水泥固化黏土强度与硬度的相关性进行了试验研究;探讨了加固土的硬度与养护时间、水泥掺量以及强度与硬度之间的关系。试验结果表明:上海黏土水泥土强度和硬度呈正比相关,对数坐标下的强度和硬度有着形如lnq_u=ap+b的线性关系。养护初期,硬度增长速度大于水泥土强度增长速度。养护后期,强度增速大于硬度增速。     

路邦土壤固化剂固化土的工程性质试验

采用的路邦EN-1型土壤固化剂是一种高分子化学土壤固化剂。它的固化原理是:与水稀释后,可与土壤中的矿物质及土壤颗粒发生溶解、结晶、吸收、扩散、再结晶的链式化学反应,从而将路基凝结成整体结实、持久的板体结构,显著降低路基弯沉,提高路基回弹模量,提高路基密实度,增强路基的承载能力,并显著改善路基的水稳性。通过试验,对土壤的干密度稍有提高;无侧限抗压强度及承载比(CBR)明显提高;不同龄期浸水的无侧限抗压强度随龄期增加而增加。     

碱土金属盐合成剂对水泥稳定土改良效果的试验研究

碱土金属盐合成剂是一种新型水泥稳定土添加剂,其作用机理是通过水合作用与水泥形成交叉结构的晶体,进而提升水泥稳定土的强度和韧性水平。为研究碱土金属盐合成剂的实际改良效果,分别对加有碱土金属盐合成剂和无添加剂的水泥稳定土进行1d、3d、7d、14d、28d龄期时的无侧限抗压试验、抗拉试验、回弹模量试验。试验结果表明：水泥稳定土经改良后,其抗拉、抗压强度及回弹模量都得到了显著提升,弥补了水泥稳定土韧性较差、抗拉强度不足的缺陷。