共查询到18条相似文献，搜索用时 359 毫秒
1.
真空-堆载联合预压法是加固饱和软粘土的理想方法，通过试验，观测路基的表面沉降和水平位移，说明真空预压能使地基产生较大的沉降速率，同时提高路基的稳定性，侧向位移量和位移速率与荷载大小的相关性比较明显。 相似文献
2.
真空预压技术加固海堤深厚软基原型试验研究 总被引：4，自引：0，他引：4
真空荷载提供了一种减少堤坝软土地基固结时间的选择. 本文开展了一个海堤全断面的试验及原型观测研究. 试验堤高5. 5 m, 22 m深且三角形布置的塑料排水板作为竖向排水通道, 现场布置了水平测斜和沉降仪等观测仪器, 埋设在不同地基深度的孔隙水压力计用来量测真空-堆载联合荷载下的地基中超静孔隙水压力的变化. 通过场地条件分析、高真空度维持和真空卸载, 得到了系统的沉降变形和孔隙水压力资料, 试验结果验证了真空-堆载联合预压加固海堤软土地基的效果. 相似文献
3.
采用真空联合堆载预压技术能通过排水固结提高地基承载力,和其他处理方法相比,能降低工程造价。结合工程实例,对加固原理、施工工艺、施工质量控制要点进行阐述,并通过监测和检测结果分析,为同类工程提供参考借鉴。 相似文献
4.
张荣喜 《世界华商经济年鉴·科学教育家》2013,(5)
近年来,堆载预压加固地基法作为一项新技术已广泛应用于填海造地、港口堆场等工程中,相对而言,此方法较为经济适用,技术上也趋于成熟.对于填海造地面临的软土地基问题,通常的处理办法有堆载预压法、真空预压法、浅层置换法等.本文以工程实例来重点论述堆载预压处理地基的施工控制要点,以求于大家共同学习、探讨. 相似文献
5.
结合一个真空预压处理人工湖海相淤泥地基的工程实例,通过对真空预压施工工艺流程及监测数据的分析,得出结论:对于海相淤泥地基,真空预压加固法是行之有效的地基处理方法,其加固效果和经济效益明显.加固后固结度和工后沉降量都达到了设计预期的目的. 相似文献
6.
林智勇 《福建工程学院学报》2016,(4):318-323
利用数值分析方法建立了软土地基模型,采用比奥固结理论,计算分析了真空预压下的软土地基流固耦合作用;并进一步分析了真空度损耗率、密封墙、塑料排水板打设深度等因素对软基加固效果的影响。分析结果表明:在抽真空早期,地表沉降增长很快,达到一定天数后,沉降值逐渐趋于稳定;真空负压沿深度、水平方向上损耗,在加固软土外围形成一个零孔隙水压力面;真空度损耗率、塑料排水板打设深度对真空预压加固软土的效果影响很大;侧向密封墙对加固区内土体影响不大,但其限制了真空负压的侧向传递,使影响区的地基沉降大幅减小。 相似文献
7.
黄建华 《福建工程学院学报》2012,(3):222-229
针对海积饱和软土地基处理实际工程中采用搅拌桩复合地基和堆载预压排水固结两种方法,进行技术与经济的优化设计分析,预测饱和软土固结度及其沉降特征。通过工程现场监测数据和实际应用效果进行对比,验证理论分析成果和固结度计算以及沉降预测的有效性,结果表明,堆载预压和排水系统的有效结合,对处理沿海饱和软土地基具有良好效果,且经济有效。 相似文献
8.
连云港海相软土具有含水量高、压缩性高、孔隙比高、强度低等特点,其工程性质较差,是该地区基础设计的重点和难点。结合某海相软土的加固处理工程,阐述了动力排水固结的加固机理,并对其加固效果进行了分析。检测结果显示,动力排水固结法处理连云港软粘土场地可以取得良好效果,其经验可供类似工程参考。 相似文献
9.
我国现有的地基处理方法很多,对于同一种软弱地基可以采用的方法常常有数种之多.由于工程地质和水文条件千变万化,各地的施工机械、技术水平、建材品种及价格差异很大,在选用地基处理方法时要因地制宜.濒海软土含水量高、孔隙大、承载力低、变形大,很难直接满足同益增长的工程建筑对地基的要求,软土地基常用的处理方法有深层搅拌法,强夯固结法,排水固结法(真空预压法、堆载预压法,真空联合堆载预压法)等. 相似文献
10.
排水固结法是先在地基中设置竖向排水井,然后利用建筑物本身重量分级逐渐加载,或是在建筑物建造以前,在场地先行加载预压,使地基发生沉降,同时强度逐步提高的方法。本论文结合工程实际说明排水固结法可以处理软粘土地基。 相似文献
11.
在考虑软土超载预压后的次固结变形特性的基础上,推导出消除使用荷载作用下的主固结所需预压时间的公式.通过室内试验研究了不同超载量和不同超载预压时间对饱和软土次固结变形的影响,对排水固结法处理软土地基有一定的参考价值. 相似文献
12.
Theone dimensionalinfinitesimalstrainconsolida tiontheorydevelopedbyTerzaghiassumedthattheper meabilityandcompressibilityoftheclayremainedcon stantduringconsolidationunderaparticularincrementofload[1] .So ,inpractice ,thetheorywasonlyapproxi matelysatisfying .Variousresearcheshavesoughttoex tendtheclassicaltheorytotakeaccountofthevariationofpermeabilityandcompressibilityduringconsolidationinoneormoreways .Thecompressibilityandcoefficientofpermeabilitywereassumedtobefunctionsofthede greeofsatur… 相似文献
13.
Undrained anisotropy and non-coaxial behavior of clayey soil under principal stress rotation 总被引：2，自引：0，他引：2
In this study, a series of undrained tests were conducted on both intact and reconstituted clay using an automatic hollow cylinder apparatus. Monotonic shearing tests with fixed principal stress directions were carried out, pure and cyclic prin- cipal stress rotation tests were also performed. The non-coaxiality, defined as the non-coincidence of the principal plastic strain increment direction and the corresponding principal stress direction, of clayey soil was studied experimentally. The effects of the intermediate principal stress, shear stress level, and inherent anisotropy were highlighted. Clear non-coaxiality was observed during pure principal stress rotation, in both intact and reconstituted clay. The influence of the intermediate principal stress pa- rameter, shear stress level, and inherent anisotropy on the non-coaxial behavior of the clayey soil was found to be insignificant when compared with the sand. The non-coaxial behavior of the clayey soil depended more on the stress paths. Under undrained conditions, the contribution of elastic strain to the direction of the total principal strain increment cannot be ignored. 相似文献
14.
There exists a critical cyclic stress ratio when sand or clay is subjected to cyclic loading. It is an index distinguishing stable state or failure state. The soil static and dynamic universal triaxial and torsional shear apparatus developed by Dalian University of Technology in China was employed to perform different types of tests on saturated soft marine clay in the Yangtze estuary. Undisturbed samples were subjected to undrained cyclic vertical and torsional coupling shear and cyclic torsional shear after three-directional anisotropic consolidation with different initial consolidation parameters. The effects of initial orientation angle of major principal stress, initial ratio of deviatoric stress, initial coefficient of intermediate principal stress and stress mode of cyclic shear on the critical cyclic stress ratio were investigated. It is found that the critical cyclic stress ratio decreases significantly with increasing initial orientation angle of major principal stress and initial ratio of deviatoric stress. Compared with the effects of the initial orientation angle of major principal stress and initial ratio of deviatoric stress, the effect of initial coefficient of intermediate principal stress is less evident. Under the same consolidation condition, the critical cyclic stress ratio from the cyclic coupling shear test is lower than that from the cyclic torsional shear test, indicating that the stress mode of cyclic shear has an obvious effect on the critical cyclic stress ratio. The main reason is that the continuous rotation in principal stress directions during cyclic coupling shear damages the original structure of soil more than the cyclic torsional shear does. 相似文献
15.
土的固结过程与渗透性质关系密切,但传统的固结仪不能进行渗透试验。该文研制了一种渗透固结装置,既能进行固结试验和渗透试验,又能测量固结过程中的孔压。装置构造简单,操作便捷,密封性能好,可自动记录孔压、时间等参数。该装置应用于研究生的土工试验教学,促进了土力学理论与实践教学的融合,不仅加深了学生对理论知识的理解,提高了学生分析和解决问题的能力,还增强了学生的科研思维和动手实践能力,从而提高了人才培养质量。 相似文献
16.
Dragload and Downdrag Performances of Inclined Pile Group Embedded in Consolidating Soil 总被引：1，自引：1，他引：0
The performance of inclined pile group embedded in consolidating soil under surcharge load was investigated by experiment in comparison with vertical pile group and single pile under the same conditions; dragload, downdrag, and layered soil settlement were measured. A three-dimensional numerical model was built via FLAC3D software, and verified by the experimental results. Influence factors, such as consolidation time, pile spacing, and pile tilt angle were analyzed. The results show that dragload of inclined pile group increases with the increase of consolidation time and pile spacing or the decrease of pile tilt angle. Downdrag of inclined pile group increases with the increase of consolidation time, pile spacing and pile tilt angle. 相似文献
17.
受堆载超载影响下的桩基性状分析研究 总被引：5，自引：0，他引：5
地面大面积堆载超载常常使地基软弱土体产生侧向变形，从而挤压邻近桩基，因而对桩基上部的构筑物不利。将桩体等效成板桩，用梁单元模拟，以一现场试验为依据，章采用平面有限元分析了堆载超载影响下的相邻桩基性状。 相似文献
18.
XIE Kang-he Ql Tian DONG Ya-qin 《浙江大学学报(A卷英文版)》2006,7(8):1358-1364
INTRODUCTION Conventional consolidation analysis based on Terzaghi’s one-dimensional theory neglects the non-linearity of soil for the sake of mathematical expediency, which is considered to be one of the theory’s shortcomings. Many researchers have pro-posed one-dimensional (1D) consolidation models where the coefficient of volume compressibility mv, coefficient of permeability kv, and coefficient of consolidation cv, vary with either depth or time. Schiffman (1958), Davis and Raymon… 相似文献