Effect of the pressurized duration on improving dredged slurry with air booster vacuum preloading     

Shanwei Ke  Peng Wang  Xueyue Geng  Jun Hai  Jinqiang Jin 《Marine Georesources & Geotechnology》2020,38(8):970-979

Abstract

Compared with traditional vacuum preloading, air booster vacuum preloading is more effective at strengthening dredged slurry and improving the consolidation process. Although many engineering practices have shown that the pressurized duration has a significant effect on the reinforcement effect, there is no standard available for determining the pressurized duration. In this study, five dredged slurry samples were tested to examine the effect of different pressurized durations on the consolidation. An extensive monitoring system was used to measure the vacuum pressure, pore water pressure, settlement, and water discharge during the test, while the water content and shear strength were measured after the test. The collected monitoring data were comprehensively analyzed to evaluate the reinforcement effect. The results revealed that the pressurization system can be used to reinforce deep dredged slurry and make the whole soil layer more homogeneous. If the pressurized duration is too short, the dissipation of pore water pressure is too little to achieve the pressurization effect. If the pressurized duration is too long, too much gas will be in the soil and enter the vacuum system, which will significantly reduce the vacuum pressure and thus the reinforcement effect. Based on these findings, the optimal pressurized duration was obtained.  相似文献   

越南金瓯化肥项目真空预压监测成果分析   总被引：2，自引：0，他引：2  

甘七零 《岩土工程技术》2010,24(2):58-61

越南金瓯化肥项目软基采用真空预压法处理,在预压过程中采用了膜下真空度、地面沉降、分层沉降、地下水位、孔隙水压力、深层水平位移等多种监测方法。对监测目的、方法做了介绍,根据监测的数据预测了最终沉降,计算了固结度,为卸载提供了依据。  相似文献   

考虑加载过程的真空预压轴对称解析解     

彭劼  董江平  宋恩润  洪雷 《岩土力学》2010,31(Z1):79-85

本文在砂井地基轴对称等应变方程的基础上,推导了真空预压荷载下的轴对称孔压、固结度解析解,该解析解利用函数模拟孔压在地表的初始条件,以考虑真空荷载的施加过程,解决了以往真空预压解孔压边界条件和初始条件在地表处的矛盾。同时也可考虑涂抹和井阻等因素,更加接近实际工程情况。通过例题与其他解答及数值解进行了验证、比较,证明了该解答的适用性,可进一步用于实际工程的设计计算。  相似文献   

真空预压作用下软土地基固结的分形研究     

吴春勇  王清  吕洪斌 《探矿工程》2005,32(12):6-9

随着真空预压法在软土地基处理中的逐步应用，其软土固结的机理一直是探讨的课题，分形理论的产生为软土这一非线性系统研究提供了新的思路。针对真空预压作用下软土地基固结中存在的问题以及土体研究中的一些分形现象，用分形理论对其研究前景等进行了探讨，从宏观和微观两方面论证了真空预压作用下软土地基固结的分形研究是可行的。  相似文献   

X射线荧光光谱法测定地质样品中的氯和硫     

袁家义  白雪冰王卿 周长祥 《岩矿测试》2004,23(3):225-227

使用粉末压片-X射线荧光光谱法测定地质样品中的Cl和S，探讨了样品放置时间、环境以及建立真空的时间对测量结果的影响。Cl的精密度(RSD，n=6)小于10％，S的精密度(RSD，n=6)小于5％。Cl和S的方法检出限分别为14和11μg／g，采用国家标准物质分析验证方法，其结果与标准值相符。  相似文献   

负压条件下考虑土体损伤和流变的有限元分析   总被引：8，自引：2，他引：8  

吴跃东  余湘娟  殷宗泽 《岩土力学》2002,23(2):137-141

介绍了在负压条件下软基加固的各种理论计算，并采用平面应变有限元法进行分析，计算中考虑了土体的流变和施工扰动引起的损伤。计算结果与某高速公路试验段现场观测的结果比较接近，说明计算方法是合理可行的。  相似文献   

三种降低土料含水量方法的试验研究     

张林洪  吴华金  王甦达 《岩土工程技术》2007,21(4):170-175

从原理分析,采用疏干排水、真空排水、电渗排水都能排除土料中的水分。为了确定能否在工程中使用,对三种方法进行试验。三种方法开始时排水速率较快,都能降低土体的含水量,提高土体密度。得出电渗方法排水效果最好。  相似文献   

真空加固前后软土工程地质性质研究   总被引：1，自引：1，他引：1  

秦焱  王清  侯红英 《世界地质》2007,26(1):89-93

借助X-射线、扫描电镜及计算机图像处理等技术，对海积软土真空预压加固前后的结构特征进行定量分析，并结合室内试验，对比研究土体微观结构和工程性质的变化，探讨真空预压加固的机理。研究表明真空预压加固效果明显，软土工程性质得到改善。加固前软土的微结构以蜂窝状、团粒-絮凝状结构为主，大孔隙较多；加固后以团粒状结构为主，粒内和粒间孔隙变小；加固后结构单元体和孔隙未形成明显的定向性。这与堆载预压加固的结构变化显著不同。真空预压加固是在球应力即等向压力下固结。  相似文献   

A simple Newtonian model for the fractal accelerating Universe     

P.?V.?Gruji?Email author 《Astrophysics and Space Science》2005,295(3):363-374

We propose a simple mechanism for driving the recently detected non-decelerating expansion of the observable Universe. It is based on the assumption of the predominance of the vacuum energy over the inert matter and a fractal structuring of the latter. The Newton’s universal gravitational force ensures the attraction between celestial bodies at small and medium astronomical distances, but gives rise to the repulsive interaction between mutually very separated cosmic subsystems, like clusters and superclusters, and thus to the observed accelerating expansion and the fractal structuring.  相似文献   

Gravitational Lensing in A Model With Non-Interacting Matter and Vacuum Energies     

A.-M.?M.?Abdel-RahmanEmail author  Mohsin?H.?A.?Hashim 《Astrophysics and Space Science》2005,298(4):519-523

The gravitational lensing rate in a flat cosmological model of noninteracting matter and vacuum energies is investigated. It turns out to be very close to that in a recently studied modified general relativity model and that it is consistent with observations.  相似文献