静力触探实验数据库的建立及土体参数相关性分析     

徐佳成  陈祖煜  王玉杰 《岩土工程技术》2010,24(6):307-311

静力触探实验以其连续性、重现性好及可靠性高等优点在现场实验中得到广泛的应用,但目前国内外对于其实验数据的数字化管理及其相关性分析方面的研究仍然较少。借助VBA语言对Excel进行二次开发,建立了静力触探实验数据库。该数据库不但具有信息量大、操作简单、代码开放等特点,而且具有随着库中数据量的丰富,其分析结果可靠性越高的优点。并且以该库中的上海地区18个工程项目的岩土工程勘察的实验数据为基础,分别对静力触探实验比贯入阻力B与土的压缩模量B、固结快剪指标（Ccq、φcq）、以及三轴固结不排水指标（Ccu、φcu）做了相关性分析,得到三组关系式。对这几组关系式的显著性检验的结果表明相关性很好,可为地层条件与上海地区类似的工程设计作为参考依据。  相似文献   

Application of Dynamic Compaction in Highway: A Case Study   总被引：1，自引：0，他引：1  

Linchang Miao  Gong Chen  Zhenshun Hong 《Geotechnical and Geological Engineering》2006,24(1):91-99

The application case of dynamic compaction (DC) is realized in highway. In this paper, the in situ tests for evaluating effectiveness of DC are performed on a liquefiable soil and soft soil interbedding foundation encountered in highway engineering practice. Excess pore pressure, total surface settlement and lateral deformation under DC impact are measured and analysed. The cone penetration test (CPT) and spectral analysis of surface wave (SASW) are used for investigating the compaction effectiveness. The formulation of the predicting improvement depth of the DC is presented according to the pseudo-static mechanics method and is of obvious meaning of soil mechanics compared with Mendard’s formulation. The calculating results of the formulation of improvement depth of the DC are agreement with the measuring results. The investigation results indicate that the DC technique is an effective way for improving liquefiable soil and soft soil interbedding foundation in highway engineering practice.  相似文献   

江苏连云港地区滨海相软土地质特性研究     

陈艺南  谈清等 《江苏地质》2001,25(2):106-110

根据江苏连云港地区大量的工程地质勘察资料，就该区软土层的因类型、物理力学特性、室内试验问题、现场原位测试，特别是力学指标的确定进行了深入的探讨和分析，结果表明：室内试验确定连云港 地区软土力学指标误差大，有些指标与实际误差在2倍以上，常难以气氛。用十字板、CPT方法有较好的效果。  相似文献   

Liquefaction analysis and soil improvement in Beydag dam     

Davut Yılmaz  Fatih Babuçcu  Serhat Batmaz  Fatih Kavruk 《Geotechnical and Geological Engineering》2008,26(2):211-224

Beydag dam is under construction on Kucukmenderes River for irrigation purposes. Due to the scarcity of core material and liquefaction of alluvium at the dam site, the original design was changed to Roller Compacted Concete (RCC) from rockfill dam with claycore. Although the new design was safer, it nearly doubled the cost of the dam, so the owner, State Hydraulic Works of Turkey, (DSI) set out to find more economical but equally safe alternative. Since jet-grouting is a cheap ground improvement tool in Turkey, such an alternative was developed for the ground improvement against liquefaction together with concrete face rockfill dam sitting on top of improved ground. This paper presents a detailed discussion of how the new alternative was developed and evaluated: it discusses the determination of jet grouting pattern, the placement of jet grouted blocks, and the assesment of liquefaction. On one hand the soil cement strength of jetgrout columns, internal friction angle of alluvium and rockfill were important in determining the dimensions of the blocks, on the other hand the location of the blocks were highly affected by the areas where liquefaction occurred. One of the most important parameter that has a considerable influence in delineating the boundary betweeen liquefaction and non-liquefaction was the value of stress reduction coefficient (r _d), being primarily sensitive to the weight of overburden, which is calculated by the height from the face of dam to the depth where the calculation was made. This approach is justified by two-dimensional ground response analysis. Most importantly, this paper shows that there exists an alternative solution for building dams on the liquefaction prone sites without removing alluvium by using a well known jet grouting technique for improving ground at only selected places.  相似文献   

Documentation of soil conditions at liquefaction and non-liquefaction sites from 1999 Chi–Chi (Taiwan) earthquake     

Daniel B. Chu  Jonathan P. Stewart  Shannon Lee  J. S. Tsai  P. S. Lin  B. L. Chu  Raymond B. Seed  S. C. Hsu  M. S. Yu  Mark C. H. Wang 《Soil Dynamics and Earthquake Engineering》2004,24(9-10):647

The 1999 Chi–Chi, Taiwan, earthquake provides case histories of ground failure and non-ground failure that are valuable to the ongoing development of liquefaction susceptibility, triggering and surface manifestation models because the data occupy sparsely populated parameter spaces (i.e. high cyclic stress ratio and high fines content with low to moderate soil plasticity). In this paper, we document results from several large site investigation programs conducted in Nantou, Wufeng and Yuanlin, Taiwan. The seismic performance of the investigated sites include non-ground failure building and free-field sites, building sites with partial foundation bearing failures, free-field lateral spread sites, and free-field level ground sites with sediment boils. Field and laboratory investigation protocols for the sites are described, including cone penetration testing (some with pore pressure and shear wave velocity measurements) and rotary wash borings with standard penetration testing (including energy measurements). Implications of the SPT energy measurements with respect to established guidelines for the estimation of SPT energy ratio (including short rod corrections) are presented. Finally, data for three example sites are shown that illustrate potential applications of the data set, and which also demonstrate a condition where existing liquefaction analysis procedures fail to predict the observed field performance.  相似文献   

基于Downhole工艺的海底静力触探及其设备研制     

陈奇  石要红  潘毅  补家武 《海洋工程》2007,25(4):73-76

论述基于Downhole CPT的海底静力触探工艺和实施方案,并在此基础上研制了适用于水深10~100 m,触探最大深度120 m的海底静力触探设备。对设备中的管内锥探总成、海底机座以及推进速度控制策略等核心问题进行了探讨。码头与海底试验中,触探数据结果与钻探取样基本符合,验证了工艺方案与触探设备达到了预期的工艺要求。  相似文献   

唐山地区可液化场地标准CPT指标及其与剪切波速的关系   总被引：1，自引：0，他引：1  

邱毅  曹振中  袁晓铭  徐进 《地震工程与工程振动》2010,30(2)

无论从以往大地震的经历还是未来潜在地震危险的角度,唐山地区都是一个研究液化的良好的实验场,对其可液化场地获取符合国际标准的、代表目前国际上液化势衡量指标发展趋势的CPT测试结果,对积累液化研究基础数据、研究液化前后场地的抗液化性能变化以及发展新的液化预测方法应是有意义的工作。本文采用国际标准的CPT技术对唐山地区可液化场地进行实地勘察测试,得到了锥尖阻力和侧壁摩阻力这两项新指标,提出了可液化场地剪切波速构造,同时利用系统的优势,得到了可液化场地锥尖阻力与剪切波速间的关系式,分析了可液化场地CPT剖面和剪切波速特征。几个方面的分析表明,给出的结果具有可靠性。  相似文献   

上海地区扁铲侧胀试验与其他原位试验结果的相关性分析   总被引：2，自引：0，他引：2  

唐世栋  林华国 《岩土力学》2005,26(3):392-396

由于扁铲侧胀试验（DMT）在国内应用时间不长,如何合理地解释和应用DMT试验成果尚待进一步探讨。与其他原位试验结果进行对比分析是研究方法之一。介绍了多元回归在岩土工程相关分析中的应用。根据上海地区多个工程的扁铲侧胀试验、十字板剪切试验、标贯试验和静力触探试验的数据,通过选元分析和多元回归,得出扁铲侧胀试验与其它原位试验的相关关系,可供勘察设计相关人员参考使用。  相似文献   

Assessment of direct CPT and CPTU methods for predicting the ultimate bearing capacity of single piles   总被引：1，自引：0，他引：1  

Guojun Cai  Songyu Liu  Liyuan Tong  Guangyin Du 《Engineering Geology》2009,104(3-4):211-222

Twelve methods to determine axial pile capacity directly based on cone penetration test (CPT) and piezocone penetration test (CPTU) data are presented, compared and evaluated. Analyses and evaluation were conducted on three types of piles of different size and length. All the tested piles have failed at the end of static load test. Both the CPT methods and the CPTU methods were used to estimate the load bearing capacities of the investigated piles (Q_p). The static load test was performed to determine the measured load bearing capacities (Q_m). The pile capacities determined through different methods were compared with the measured values obtained from the static load tests. Two criteria were selected as bases of evaluation: the best fit line for Q_p versus Q_m and the arithmetic mean and standard deviation for the ratio Q_p/Q_m. Results of the analyses showed that the best methods for determining pile capacity are the two CPTU methods. Furthermore, the CPTU method is simple, easy to apply, and not influenced by the subjective judgements of operating staff. Therefore, it is quite suitable for the application in pile engineering practice.  相似文献   

天津沿海地层静力触探参数与土体物理力学性质对比研究     

邢恩桥  许国辉  房俊伟  薛红 《海岸工程》2005,24(2):38-43

近年来,在天津沿海地区的工程勘察中,积累了大量的静力触探参数资料与地基土层的物理力学参数资料。利用计算机的EXCEL数据处理软件,将各地基土层的地基土物理力学参数统计平均,同时将相应土层的静力触探参数统计平均,然后对平均后的数据进行统计回归,得到静力触探参数(锥尖阻力qc与侧摩阻力fs)与地基土层物理力学参数(天然含水量ω、天然密度ρ、孔隙比e、压缩系数a及压缩模量Es)间的统计回归方程。在天津沿海地区进行工程勘察时,利用所得方程可从静力触探参数(或土体物理力学参数)方便地得到土体物理力学参数(或静力触探参数),进而可以节约外业勘察或室内试验的工作量。  相似文献