滇西陇川断陷盆地地热水化学特征及循环过程     

黄琴辉  张华  康晓波  王波  刘海峰  柴金龙  黄钊  王燕 《中国岩溶》2020,39(6):793-801

通过对陇川盆地开展地热地质调查，查清其地热资源分布:盆地内共出露地热点11处，热储结构类型为带状型和层状型，盆地中部为层状型，两侧盆地边缘为带状型，其中北西部受断裂控制明显，南东部受节理裂隙控制明显。其储热层为变质岩及新近系芒棒组的花岗质砂砾岩、细砂岩；地热水受大气降水影响明显，循环深度都在1 600 m以上，大部分在1 800~2 400 m之间，主要来源于深部热源，通过断裂、裂隙及砂砾石孔隙作为导水、储水上涌通道，接收来自山区补给的地下水混合出露于地表，补给距离在1.5 km以上，如南宛河温泉温度最高，地下水循环深度最深，补给距离最远，达10 km；盆地北东和西部水温高，循环深度深。   相似文献   

Field study of monotonic and cyclic lateral behaviour of piles in soft soils improved with and without vacuum preloading     

Fu  Hongtao  Wang  Jun  Cai  Yuanqiang  Jin  Jinqiang  Dong  Quanyang  Hu  Xiuqing  Wang  Peng  Geng  Xueyu  Zhang  Dikang 《Acta Geotechnica》2020,15(11):3183-3192

Acta Geotechnica - Project Oufei is the largest individual reclamation project in Wenzhou city, China, and the main infrastructure consists of seawalls, sluices and separation dikes. These...  相似文献   

张掖盆地地下水硝酸盐污染与人体健康风险评价     

盛丹睿  温小虎  冯起  武君  司建华  吴敏 《中国沙漠》2019,39(5):37-44

地下水是张掖盆地的重要水资源，其硝酸盐污染尚未得到足够重视。对张掖盆地2004、2015年地下水硝酸盐浓度进行了系统分析，并采用美国环境保护署（USEPA）推荐的健康风险评价模型评估了地下水硝酸盐的健康风险。结果表明：自2004年以来张掖盆地地下水硝酸盐污染日趋严重。2015年硝酸盐浓度最高已达到283.32 mg·L^-1，17.61%的采样点硝酸盐氮浓度超过GB5749-2006《生活饮用水卫生标准》中饮用地下水限量值（20 mg·L^-1）。研究区人群经皮肤接触途径摄入硝酸盐的健康风险在可接受水平，而饮水摄入硝酸盐的健康风险较高，总风险中饮水途径引起健康风险的贡献率占99.40%，远大于皮肤接触途径。儿童经饮水摄入和皮肤接触两种途径的健康风险均显著高于成人，分别为成人的1.544倍和1.039倍。32.39%的采样点地下水硝酸盐对儿童的健康风险超出了可接受水平，14.79%的采样点地下水硝酸盐对成人的健康风险不可接受。甘州区城区、临泽县北部边缘及高台县城区周围硝酸盐浓度最高，这些区域内所有人群都面临硝酸盐引发的高健康风险，其余区域硝酸盐引发的健康风险相对较低。  相似文献   

湍流度随高度的变化及其对城市宏观地形的依赖     

李大全  孙武  欧阳睿康  黄盛  高梦媛  李庆祥  黄启明 《热带地理》2019,39(3):365-376

分别构建广州主建成区垂直比例尺为1﹕2 000、1﹕1 000和1﹕500的3个建筑物模型，利用大型边界层风洞，在西北和东南两风向下，基于中性流模拟分析了复杂城市地形下湍流度随高度的变化及其对宏观地形的依赖。结果表明：风廓线指数α与不同高度的湍流度之间的关系密切，利用现有模型，根据4类粗糙度边界层和不同垂直比例尺，可确定相应的湍流度随高度变化模型的主要系数，预测精度高。城市地形下最大湍流度面发育在0~0.2 h之间狭窄的范围内。用湍流度形态指数β来表征湍流度随高度的变化，无论城市屋脊还是平坦地形，随着风程区的延伸，廓线的指数α升高，湍流度形态指数β降低。表明同一高度湍流度值具有由迎风区、丘顶区向背风区增高，沿风程逐渐增大的规律，对地形部位和风程的依赖性强，与来流翻越简单地形时的特征一致。  相似文献   

A micro-mechanics-based elastoplastic friction-damage model for brittle rocks and its application in deformation analysis of the left bank slope of Jinping I hydropower station     

Hu  Kun  Shao  Jian-Fu  Zhu  Qi-Zhi  Zhao  Lun-yang  Wang  Wei  Wang  Ru-Bing 《Acta Geotechnica》2020,15(12):3443-3460

Acta Geotechnica - This study develops a micro-mechanics-based elastoplastic damage model within the framework of irreversible thermodynamics. In the model, damage is related to growth of...  相似文献   

Variation behavior of pore-water pressure in warm frozen soil under load and its relation to deformation     

Zhang  Hu  Zhang  Jianming  Zhang  Ze  Zhang  Mingyi  Cao  Wei 《Acta Geotechnica》2020,15(3):603-614

Acta Geotechnica - Containing a considerable amount of unfrozen water, frozen soil may produce excess pore-water pressure under external load, especially at temperatures near the thawing point. The...  相似文献   

Mechanical behavior of porous solid considering mesoscopic elastic buckling     

Hao-Yue Zhang  Xiao-Xong Hu  Gao-Feng Zhao 《国际地质力学数值与分析法杂志》2020,44(7):962-982

In this work, the elastic buckling of porous solids was investigated using a lattice spring model (LSM). The capability of the LSM to solve elastic buckling problems was comprehensively verified by comparing well-established numerical and analytical solutions. Following this, the buckling of a porous solid was studied, in which two porous structures were considered, ie, the random porous model and the Voronoi porous model. The results reveal that both the porosity and the shape of the pores influence the elastic buckling bearing capacity of the porous solid. Finally, the mechanical responses of a porous solid with an extra high porosity (0.85) were numerically investigated. Our numerical results demonstrated that the nonlinear elastic response of the porous solid might come from its mesoscale elastic buckling. This work shows the ability and promise of using the LSM as a fundamental numerical tool for the deep investigation of the buckling mechanical behavior of porous solids.  相似文献   

不同海域沉积物对尿素吸附的实验模拟研究     

薛峤娜  胡博  谭丽菊  王江涛 《海洋学报》2018,40(10):190-199

本文对采自渤海、黄海和东海3个典型海域的沉积物进行了尿素吸附/解吸的实验室模拟研究，用Freundlich吸附模型和Henry吸附模型分析了不同沉积物对尿素吸附的热力学特性，并研究了温度、沉积物粒径、有机质含量等因素对尿素在沉积物表面吸附的影响。结果表明，沉积物对尿素的吸附/解吸过程总体呈现3个阶段:快速吸附阶段（0~5 h）—慢速吸附阶段（5~12 h）—平衡阶段（12 h之后）。当水体中的尿素浓度较低时，沉积物解吸释放尿素，随着上覆水中尿素浓度逐渐增加，沉积物对上覆水中的尿素产生吸附行为，各海区沉积物对尿素的吸附能力由强至弱依次为渤海、东海、黄海，这可能与沉积物的类型有关。Freundlich方程和Henry方程均可模拟沉积物对尿素的吸附，温度、粒径以及沉积物中有机质含量等因素均对尿素在沉积物上的吸附产生影响，随着温度升高，尿素在沉积物上的吸附量变小，沉积物粒径越小，有机质含量越高，吸附尿素的能力越强，因此，揭示尿素在沉积物表面的环境行为时，必须考虑以上因素的影响。  相似文献   

机载激光雷达测深技术研究与进展     

王鑫  潘华志  罗胜  杨鑫丽 《海洋测绘》2019,39(5):78-82

当前包括内河、水库及海域在内的水上、水下地形测量任务需求不断增加,进行水域或海洋测绘领域研究已提升到新的国家战略性高度。首先介绍了当前机载激光雷达水深测量的基本原理;概括总结了激光测深中的波形处理、波浪潮汐改正、折射改正、航带拼接与数据融合等关键技术,对测深的精度及误差影响进行了分析。最后结合当前技术的发展及新技术的出现,对未来机载激光雷达测深技术的发展进行了展望。  相似文献   

Dispersion features of transmitted channel waves and inversion of coal seam thickness     

Ze’an Hu  Pingsong Zhang  Guangquan Xu 《Acta Geophysica》2018,66(5):1001-1009

In-seam seismic survey currently is a hot geophysical exploration technology used for the prediction of coal seam thickness in China. Many studies have investigated the relationship between the group velocity of channel wave at certain frequency and the actual thickness of exposed coal beds. But these results are based on statistics and not universally applicable to predict the thickness of coal seams. In this study, we first theoretically analyzed the relationship between the depth and energy distribution of multi-order Love-type channel waves and found that when the channel wave wavelength is smaller than the thickness of the coal seam, the energy is more concentrated, while when the wavelength is greater than the thickness, the energy reduces linearly. We then utilized the numerical simulation technology to obtain the signal of the simulated Love-type channel wave, analyzed its frequency dispersion, and calculated the theoretical dispersion curves. The results showed that the dispersion characteristics of the channel wave are closely related to the thickness of coal seam, and the shear wave velocity of the coal seam and its surrounding rocks. In addition, we for the first time realized the joint inversion of multi-order Love-type channel waves based on the genetic algorithm and inversely calculated the velocities of shear wave in both coal seam and its surrounding rocks and the thickness of the coal seam. In addition, we found the group velocity dispersion curve of the single-channel transmitted channel wave using the time–frequency analysis and obtained the phase velocity dispersion curve based on the mathematical relationship between the group and phase velocities. Moreover, we employed the phase velocity dispersion curve to complete the inversion of the above method and obtain the predicted coal seam thickness. By comparing the geological sketch of the coal mining face, we found that the predicted coal seam thickness is in good agreement with the actual thickness. Overall, adopting the channel wave inversion method that creatively uses the complete dispersion curve can obtain the shear wave velocities of the coal and its surrounding rocks, and analyzing the depth of the abruptly changed shear wave velocity can accurately obtain the thickness of the coal seam. Therefore, our study proved that this inversion method is feasible to be used in both simulation experiments and actual detection.  相似文献