Cement Deep Soil Mixing (CDSM) for Solidification of Soft Estuarine Sediments     

A. Maher  W. S. Douglas  D. Yang  F. Jafari  V. R. Schaefer 《Marine Georesources & Geotechnology》2013,31(3-4):221-235

A preliminary study was conducted to determine the potential for cement deep soil mixing (CDSM) technology as a method for in-situ solidification of contaminated river and estuarine sediments. The study was conducted in Newark Bay, near the mouth of the Passaic River, New Jersey. The primary objective of the study was to evaluate the viability of CDSM for the in-situ S/S with a focus on: 1) determining the correct mix of the cement slurry, which provides rapid stabilization of the sediment matrix, 2) potential resuspension of solids during CSDM operations, 3) the effects of high organic content on the solidification process, and 4) the feasibility of using conventional dredging/extraction methods once the sediments have been stabilized and allowed to cure. The results of the study show CDSM slurry mixtures, as low as 7% in cement content, result in significant solidification and strength gain of in-situ sediments under ambient conditions. In sediments with very high organic contents (> 20%), the slurry mix would need to be adjusted to account for retardation effects of organics on cement hydration. Sediment resuspension during application was shown to be minimal at a distance of as little as 75 feet from the mixing head. Strength gains were considerable, effectively consolidating the sediment particles in a secure matrix, but not so high as to preclude extraction of solidified sediments with conventional dredging equipment. Dredged solidified sediment exhibited characteristics of a stiff glacial clay, and as such was easier to handle and transport than untreated dredged sediments. This technique has high potential to be used as an interim remedial measure prior to either extraction and decontamination/disposal or proper capping.  相似文献   

巴彦淖尔市水泥混凝土施工冻害指数分析     

高贵荣  毕炜  杨北华  杨青  张静  王瑞红 《内蒙古气象》2012,(5):33-35

为了便于开展冬季水泥混凝土施工气象服务,选用临河和海流图（乌拉特中旗）测站近10a的气象资料分别作为河套和后山地区的气象数据．选取逐日最高气温、最低气温、定时相对湿度、最小相对湿度、降水量、定时风速,经过筛选、统计、计算,得出河套地区水泥施工适宜时段为4月上旬末至10月中旬,后n1地区水泥施工适宜时段为4月中旬末至10月上旬．这一研究结果町以提升冬季建筑施工气象服务的针对性和实用性。  相似文献   

水泥粘结剂基材边坡绿化技术研究——室内试验研究     

黄俊  任新红  罗阳明 《地质灾害与环境保护》2009,20(1)

通过对水泥厚层基材的直剪试验、无侧限抗压试验和三相分布、养分及pH值测定结果的综合分析,论证了水泥粘结基材替代化学粘结基材进行边坡绿化的技术可行性;同时通过比选优化了基材配比.  相似文献   

水泥粘结剂基材边坡绿化技术研究——现场试验研究     

黄俊  任新红  罗阳明 《地质灾害与环境保护》2009,20(1)

通过现场工程试验研究,进一步论证了水泥粘结基材替代化学粘结基材的岩质边坡绿化技术的可行性;同时提出了岩质边坡工程绿化应按"循序渐进"来进行植被恢复的理念.  相似文献   

水泥粉喷桩在软基中的应用     

焦银禾 《中国勘察设计》2009,(8):54-55

简要阐述了水泥粉喷桩设计要求、施工工艺、效果检测,对地基承载力的影响,具有广阔的应用前景。  相似文献   

水泥粉煤灰碎石桩工程实例     

尚晋敏 《中国勘察设计》2009,(6):74-76

通过某高层住宅地基处理的设计实例,分析了水泥粉煤灰碎石桩（CFG桩）的特性,指出了水泥粉煤灰碎石桩使用时须注意的要点。  相似文献   

世界屋脊高海拔2000t／d级新型干法水泥生产线     

郭天代  陈冬珍 《中国勘察设计》2009,(11):49-53

已建成投产的西藏高天水泥有限公司2000t／d级熟料新型干法水泥生产线是目前世界上海拔最高的规模最大的采用窑外分解技术的水泥生产线,也是天津院承担设计的高海拔地区第一条2000t／d级水泥生产线。设计方案适应当地海拔高、缺氧、四季昼夜温差大的气候及原、燃材料等条件。年平均大气压为65．1kPa,约为平原地区的62％,工程设计面临很多困难条件,无国内外经验可借鉴,天津院依托自身技术优势,勇于创新,开发了具有自主知识产权的高海拔新工艺、新装备,如高原型预热器、分解炉、熟料冷却机等并供货。回转窑、原料粉磨、水泥粉磨、煤磨、石灰石破碎机均由天津院设计。燃烧器、选粉机、风机、空压机等所有系统配套的机械、电气设备及元件在设计选型时均进行高原校正。同时针对高海拔地区做了大量的研究和开发工作,降低工程投资,达到了节能、降耗、减少污染、改善环境、提高产品质量、激发企业竞争力的目的。  相似文献   

塔中上奥陶统方解石胶结物类型及其形成环境     

王振宇  ;吴丽  ;张云峰  ;韩剑发  ;张丽娟 《西安地质学院学报》2009,(3):265-271

通过对塔中地区上奥陶统数百块碳酸盐岩薄片和抛光面中各种方解石胶结物特征和成因的观察,并结合微量元素和碳、氧同位素分析,共识别出11种胶结物类型。详细描述了各胶结物的特征,并确定了胶结物的分布和形成次序。在此基础上对该区碳酸盐岩方解石胶结物形成环境进行了分析,共划分出海底成岩环境、大气水成岩环境和埋藏成岩环境。从而为该区孔隙演化史的建立和有利勘探目标预测提供了有力的依据。  相似文献   

水泥固化锌污染土电阻率与强度特性研究     

张少华  李熠  寇晓辉  董晓强 《岩土力学》2015,36(10):2899-2906

以标准砂及普通硅酸盐水泥为试验材料,制作水泥固化锌污染土样,进行了一系列电阻率和无侧限抗压强度试验。研究了交流电频率对水泥固化锌污染土电阻率的影响、不同含量锌离子对水泥缓凝作用的影响、锌离子含量和龄期分别对水泥土电阻率和强度的影响、电阻率与无侧限抗压强度的关系。结果表明：电阻率随电流频率的增加而明显降低,尤其当频率低于50 kHz时为甚;不同含量的锌离子对水泥土的缓凝作用影响明显,随着锌离子含量的增大,水泥土强度的充分发挥所需时间逐渐增长,但在锌离子含量为500 mg/kg时,缓凝作用表现异常;电阻率和强度均随龄期的增加而增长,随锌离子的含量的增加上下波动,电阻率在锌离子含量为50 mg/kg和500 mg/kg时出现极值,强度在锌离子含量为100 mg/kg和500 mg/kg时出现极值;在各个龄期下,电阻率与强度均呈现出很好的线性关系。  相似文献   

Diagenetic fluid evolution and water-rock interaction model of carbonate cements in sandstone: An example from the reservoir sandstone of the Fourth Member of the Xujiahe Formation of the Xiaoquan-Fenggu area,Sichuan Province,China   总被引：1，自引：0，他引：1  

LIU SiBing  HUANG SiJing  SHEN ZhongMin  Lü ZhengXiang  SONG RongCai 《中国科学:地球科学(英文版)》2014,57(5):1077-1092

Carbonate cement is the most abundant cement type in the Fourth Member of the Xujiahe Formation in the Xiaoquan-Fenggu area of the West Sichuan Depression. Here we use a systematic analysis of carbonate cement petrology, mineralogy, carbon and oxygen isotope ratios and enclosure homogenization temperatures to study the precipitation mechanism, pore fluid evolution, and distribution of different types of carbonate cement in reservoir sand in the study area. Crystalline calcite has relatively heavy carbon and oxygen isotope ratios(δ13C = 2.14‰, δ18O = -5.77‰), and was precipitated early. It was precipitated directly from supersaturated alkaline fluid under normal temperature and pressure conditions. At the time of precipitation, the fluid oxygen isotope ratio was very light, mainly showing the characteristics of a mixed meteoric water-seawater fluid(δ18O = -3‰), which shows that the fluid during precipitation was influenced by both meteoric water and seawater. The calcite cement that fills in the secondary pores has relatively lighter carbon and oxygen isotope ratios(δ13C = -2.36‰, δ18O = -15.68‰). This cement was precipitated late, mainly during the Middle and Late Jurassic. An important material source for this carbonate cement was the feldspar corrosion process that involved organic matter. The Ca2+, Fe3+ and Mg2+ ions released by the clay mineral transformation process were also important source materials. Because of water-rock interactions during the burial process, the oxygen isotope ratio of the fluid significantly increased during precipitation, by about 3‰. The dolomite cements in calcarenaceous sandstone that was precipitated during the Middle Jurassic have heavier carbon and oxygen isotope ratios, which are similar to those of carbonate debris in the sandstone(δ13C = 1.93‰, δ18O = -6.11‰), demonstrating that the two are from the same source that had a heavier oxygen isotope ratio(δ18O of about 2.2‰). The differences in fluid oxygen isotope ratios during cement precipitation reflect the influences of different water-rock interaction systems or different water-rock interaction strengths. This is the main reason why the sandstone containing many rigid particles(lithic quartz sandstone) has a relatively negative carbon isotope ratio and why the precipitation fluid in calcarenaceous sandstone has a relatively heavier oxygen isotope ratio.  相似文献