Inverse modelling of aquifer parameters in basaltic rock with the help of pumping test method using MODFLOW software

The origin and movement of groundwater are the fundamental questions that address both the temporal and spatial aspects of ground water run and water supply related issues in hydrological systems. As groundwater flows through an aquifer, its composition and temperature may variation dependent on the aquifer condition through which it flows. Thus, hydrologic investigations can also provide useful information about the subsurface geology of a region. But because such studies investigate processes that follow under the Earth's shallow, obtaining the information necessary to answer these questions is not continuously easy. Springs, which discharge groundwater table directly, afford to study subsurface hydrogeological processes.The present study of estimation of aquifer factors such as transmissivity (T) and storativity (S) are vital for the evaluation of groundwater resources. There are several methods to estimate the accurate aquifer parameters (i.e. hydrograph analysis, pumping test, etc.). In initial days, these parameters are projected either by means of in-situ test or execution test on aquifer well samples carried in the laboratory. The simultaneous information on the hydraulic behavior of the well (borehole) that provides on this method, the reservoir and the reservoir boundaries, are important for efficient aquifer and well data management and analysis. The most common in-situ test is pumping test performed on wells, which involves the measurement of the fall and increase of groundwater level with respect to time. The alteration in groundwater level (drawdown/recovery) is caused due to pumping of water from the well. Theis (1935) was first to propose method to evaluate aquifer parameters from the pumping test on a bore well in a confined aquifer. It is essential to know the transmissivity (T = Kb, where b is the aquifer thickness; pumping flow rate, Q = TW (dh/dl) flow through an aquifer) and storativity (confined aquifer: S = bS_s, unconfined: S = S_y), for the characterization of the aquifer parameters in an unknown area so as to predict the rate of drawdown of the groundwater table/potentiometric surface throughout the pumping test of an aquifer. The determination of aquifer's parameters is an important basis for groundwater resources evaluation, numerical simulation, development and protection as well as scientific management. For determining aquifer's parameters, pumping test is a main method. A case study shows that these techniques have been fast speed and high correctness. The results of parameter's determination are optimized so that it has important applied value for scientific research and geology engineering preparation.     

Evaluation of density in layer compaction using SASW method

SASW test, which is non-intrusive and rapid in the field application, was used to evaluate the layer density in the roller compaction without performing the complicated inversion process. The concept of normalized shear wave velocity was introduced to minimize the effect of confinement in the density evaluation. SASW test was performed to determine the shear wave velocity of the layer, and the free–free resonant column (FF–RC) test was adopted to determine the correlation between the normalized shear wave velocity and density of the site, which is almost unique independent of confinement. Testing and data reduction procedures of both tests were briefly discussed and an evaluation procedure of the field density was proposed by effectively combining in-situ shear wave velocity determined by the SASW test with the correlation between the normalized shear wave velocity and the density determined by the FF–RC test. Finally, the feasibility of the proposed method was verified by performing a field case study at Hoengsung road construction site. Field densities determined by the proposed method matched well with those determined by sand cone tests, showing the potential of applying the proposed method in the field density evaluation.     

南京红层桩基持力层承载力初探

南京红层岩性复杂，桩基持力层承载力难确定。依据南京某工程勘察资料，建立南京红层泥岩、泥质粉砂岩不同互层情况的地质模型，运用FLAC3D软件分析，并与载荷板试验结果进行对比表明：桩基持力层应选择在厚度大于两倍桩径的泥质粉砂岩地层上，避免放置于泥岩地层；载荷板试验结果偏于保守，设计时可以把这部分作为安全储备。     

新疆基础测绘元数据自动化生产技术研究

通过利用自编程序实现元数据必填属性项的自动化提取,利用程序自动化处理生成最终组织好目录的元数据成果。通过在新疆基础测绘项目的实际生产应用,对程序进行测试,证明可实现减少错漏出现,提高工作效率、降低成本、提高产品质量。     

基于FAST和SURF的遥感图像自动配准方法

提出了基于加速分割检测特征(features from accelerated segment test,FAST)和加速鲁棒性特征(speeded - up robust features,SURF)的遥感图像自动配准方法.首先对参考图像与待配准图像进行HSI变换和高斯金字塔建立;然后检测并提取FAST角点,计算各角点的SURF描述子,用K-D树匹配搜索策略得到2幅图像的匹配点对;再使用最小二乘迭代法剔除错误匹配点并拟合几何变换系数;最后执行几何变换,得到配准后的图像.将该方法分别与基于SURF自动配准方法和ENVI软件中自动获取配准点的方法进行对比实验,结果表明,利用该方法能够获得更多的匹配点对,具有更高的几何配准精度,但在尺度不变性方面略逊于SURF算法.     

Direct CPT and CPTu methods for determining bearing capacity of helical piles

Helical piles are structural deep foundation elements, which can be categorized as torque-driven piles without any limitations to implement in marine situations. Different methods are used to predict the axial capacity of helical piles, such as static analysis, but have some limitation for this type of piles on marine conditions. In situ testing methods as supplement of static analysis have been rarely used for helical piles. In geotechnical engineering practice, the most common in situ tests particularly applicable for coastal or offshore site investigation are cone penetration test (CPT) and piezocone penetration test (CPTu). The CPT is simple, repeatable, and prepares the continuous records of soil layers. In this paper, a data bank has been compiled by collecting the results of static pile load tests on thirty-seven helical piles in ten different sites including CPT or CPTu data. Axial capacities of thirty-seven helical piles in different sites were predicted by direct CPT methods and static analysis. Accuracy estimation of ten direct CPT methods to predict the axial capacity of helical piles was investigated in this study. Comparisons have been made among predicted values and measured capacity from the pile load tests. Results indicated that the recently developed methods such as NGI-05 (2005), ICP-05 (2005), and UWA-05 (2005) predicted axial capacity of helical piles more accurately than the other methods such as Meyerhof (1983), Schmertmann (1978), Dutch (1979), LCPC (1982), or Unicone (1997). However, more investigations are required to establish better correlation between CPT data and axial capacity of helical piles.     

人工冻土围压SHPB试验与冲击压缩特性分析

利用分离式Hopkinson压杆（SHPB）,以铝质套筒作为围压装置,分别研究温度为-8、-12、-16 ℃在不同应变率下的人工冻结黏土围压状态变形特征和轴向动态应力-应变关系。研究结果表明：在围压状态下,冻土呈黏塑性破坏特征;当人工冻结黏土温度为-16 ℃、平均应变率分别为410、457、525、650、827 s-1时,其最大应力分别为10.76、12.18、14.27、20.24、23.34 MPa,最大应变分别为0.081 7、0.097 2、0.105 0、0.131 0和0.166 0,表现出较强应变率效应;-12 ℃和-16 ℃时在应变率为457 s-1下的最大应力分别为8.28 MPa和12.18 MPa;当应变率相同时,温度越低,最大应力越大,冻结黏土表现出较强的温度相关性。人工冻土的动力学特性为冻土开挖方法的研究提供依据。     

富水破碎岩体注浆加固材料试验研究与应用

针对富水破碎地层注浆治理过程中传统水泥类材料难以实现注浆加固和堵水同步进行的难题,以硫铝酸盐水泥熟料和钢渣微粉为主要原材,成功制备了一种水泥基复合注浆材料（CGM）。通过与传统水泥材料进行性能对比试验,采用扫描电镜和X射线测试手段,分析了CGM材料制备工艺、组分含量和浆液制备条件对材料性能的作用规律,并检验了CGM材料的工程适用性。结果表明：CGM材料宜采用混合粉磨制备工艺,可显著提高其水化活性,且粉磨时间应不超过45 min。钢渣微粉含量越高,水灰比越大,结石体强度越低,凝结时间越长,水灰比超过1.2:1时,结石体后期会出现干缩。与传统水泥材料相比,CGM材料浆液凝结时间与黏度的环境敏感度低,具有显著的工程适用性和性能优越性。     

Influence of the ground profile on the reduction of earthquake motion at the filled man-made islands in the Kobe harbor during the 1995 Hyogoken Nambu earthquake

During the 1995 Hyogoken Nambu earthquake in Kobe, the ground motion at the filled man-made islands in the Kobe harbor was not as severe as that at the mainland. The building damage was also less compared to that on the mainland. It was found by comparative study of earthquake records that the magnitude of acceleration response on the ground surface decreases at the islands as opposed to the mainland. One dimensional effective stress analysis is adopted in this study. Input data has been generated from test results, e.g. the SPT N-value by standard penetration test and shear wave velocity V_s by PS logging. Results obtained by the analyses showed good agreement with the observed records, which is an indication of the suitability of the adopted analysis procedure. From this study, the followings are concluded. By the increase of SPT N-value of the filled layers, liquefaction near ground surface is restrained and damage modes such as ejection of water and soil can be prevented. Since the ground profile at the islands is that considerably soft filled layer and marine clay layers, etc. are present and the thickness of the surface layer is large, the initial natural period of the ground is above 1 s and the natural period is elongated further under the earthquake excitation, which is deemed to be the principal reason for the reduction of the earthquake motion at the ground surface.     

郑州市汛期FSFE02、FSFE03降水预报效果检验

利用2000－2001年6－9月份日本数值预报产品，郑州市降水实况资料及同期天气图，对日本数值预报产品在郑州市汛期天气预报中的应用效果进行了检验。结果表明；用FSFE02，FSFE03作郑州市24h汛期降水预报效果最好的是晴雨预报；各月预报能力有差异；空报率高于漏报率。在500hPa为偏南气流的条件下，该数值产品的预报效率较高；对于两层均为偏北气流及高层低槽中空西北气流的天气系统配置预报效率也较高；若中高层均为低槽，则预报效率最低。