非量测相机影像三维模型构建及精度检验

针对三维模型构建投资大、周期长、技术难度较高的问题,该文提出了基于Agisoft PhotoScan的非量测相机影像三维模型构建及精度检验方法。在对非量测数码相机数据进行预处理的基础上,利用Agisoft PhotoScan软件进行数据定向、点云提取、建立不规则三角网及数字高程模型和数字正射影像的制作;根据生成的数字高程模型和正射影像建立研究区域的三维场景模型。实验结果证明,该方法可快速建立高精度三维模型,缩短建模时间并降低投资成本。     

盾构施工参数与沉降变形关系模型构建

针对盾构施工参数变化对施工引起的地表变形的重要影响,该文构建了盾构施工参数与地表沉降变形关系模型。以北京市某地铁盾构区间施工过程中的实测数据为基础,分析了不同盾构施工参数与地表沉降变形的关联度和相关性,得到不同参数对沉降变形贡献值的大小;之后,利用多元回归模型方法建立主要影响参数与地表变形的关系模型,并进行模型的合理性检验;最后,利用该模型得到的沉降量与实测数据进行对比分析,结果显示符合性较好。     

Application of ICTs in Airspace Management and Collaborative Decision-Making—Analyzing the Risk Avoidance in the Condition of Risky Weather as an Example

The application of ICTs makes structural change of the development and effective utilization of airspace. Next generation air transportation system (NextGen) includes new automation concepts with automated information to support the traffic control decision-making. As a result, in the field of academia and industry, air traffic controllers integrate information automatically while making decisions to change the previous manually integrated and decided pattern. The safety ability of airspace is reduced and airspace system is endangered under risky weather conditions of airspace. So there is an urgent demand for new information and communication technologies. The paper is an overview of the information constitution and support of NextGen and provides the study of the development of technique of airspace collaborative decision-makings to confirm the new features based on ICTs. It contains basic application-the input of data and output of the routes of airspace management and collaborative decision-making, and general application-the choose of probability nets of avoiding risky weather, and special application-the affection in the management of the air routes, which are made up of position and direction. The research shows the accurate schedule characteristics of airspace management and collaborative decision-making based on ICTs, which made the space accurate by time accurate. Second, the visualization of airspace management and collaborative decision-making based on ICTs made the maps of flight path under mobile data quickly generated. This could make the fully development and utilization of national airspace, ensure safety, and reduce air traffic controllers’ workload and the costs in delaying and operating in risky weather.     

Community‐Derived Standards for LA‐ICP‐MS U‐(Th‐)Pb Geochronology – Uncertainty Propagation,Age Interpretation and Data Reporting

The LA‐ICP‐MS U‐(Th‐)Pb geochronology international community has defined new standards for the determination of U‐(Th‐)Pb ages. A new workflow defines the appropriate propagation of uncertainties for these data, identifying random and systematic components. Only data with uncertainties relating to random error should be used in weighted mean calculations of population ages; uncertainty components for systematic errors are propagated after this stage, preventing their erroneous reduction. Following this improved uncertainty propagation protocol, data can be compared at different uncertainty levels to better resolve age differences. New reference values for commonly used zircon, monazite and titanite reference materials are defined (based on ID‐TIMS) after removing corrections for common lead and the effects of excess ²³⁰Th. These values more accurately reflect the material sampled during the determination of calibration factors by LA‐ICP‐MS analysis. Recommendations are made to graphically represent data only with uncertainty ellipses at 2s and to submit or cite validation data with sample data when submitting data for publication. New data‐reporting standards are defined to help improve the peer‐review process. With these improvements, LA‐ICP‐MS U‐(Th‐)Pb data can be considered more robust, accurate, better documented and quantified, directly contributing to their improved scientific interpretation.     

济宁市湿地公园建设与植物景观配置初探

以济宁市湿地公园建设为例,论述了区域内湿地公园建设的基础条件、现状和发展方向。分析了不同类型的湿地公园建设重点和保护恢复的主要措施,针对济宁市河流、库塘(塌陷地)、湖泊为主体的湿地公园的植物景观建设特点,提出相关的景观建设要点和植物配置建议。     

山东省三级地下水监测站网建设思考

随着国家地下水监测工程的启动,国土资源部提出了国家、省、市新的三级地下水监测站网建设要求。该文介绍了各级地下水监测站网的基本概念、主要建设内容,各级地下水监测站网建设服务对象、基本要求,细化了各级地下水监测站网建设要求,规范了建设行动。     

Evaluation of Effective Depth of PVD Improvement in Soft Clay Deposit: A Field Case Study

This article presents a case history of determination of effective depth of prefabricated vertical drains (PVDs) under embankment loading on a very soft clay deposit in central China, near Jiujiang, Jiangxi Province. The height of the embankment was 5.3 m and construction time was about one year. The PVDs were installed to a depth of 8.5 m at a spacing of 1.5 m in a triangular pattern. Field observations and the finite element method (FEM) were employed to analyze the performance of the soft deposit during embankment construction. The influential depth of the embankment loading was evaluated based on settlement, excess pore pressure, and stress increase in subsoil, both from the observed data and FEM analysis. The effective PVD depth was determined in the following ways: (1) the depth of 5% subsoil settlement of surface settlement; (2) vertical stress increase in subsoil of 25% in-situ stress; and (3) consolidation time/PVD depth relation by FEM. Based on the analysis, the effective depth of PVDs was determined to be between 10 and 12.8 m for this field case.     

某水电站某泥石流沟综合治理概述

某水电站某泥石流沟内常年流水,属季节性排洪沟谷,水动力类型为暴雨,沟内松散物源丰富,具有泥石流发生条件。在上游区以拦挡泥石流为主,通过修建拦挡措施,减少形成泥石流的固体物质,在下游区以防水、边坡防护及引流等措施,通过修建溢流坝截断上游水流对沟内堆渣体渗流影响;通过修建排洪渠及排洪洞引流;通过削坡、修坡进行边坡维护加固。确保了导流洞出口及上下行交通洞进出口的施工期安全及运行安全。     

不同覆盖措施对高寒地区剥离的草皮块堆放温湿度及成活的影响

重大工程建设会扰动高寒草地,法规要求扰动区草皮层应予以剥离,待工程建设后再用于恢复原生植被,当前对剥离草皮堆放成活的影响研究较少。试验设计遮阳网与穿孔膜两种覆盖条件,探讨分析其对剥离的草皮块堆放与铺植利用后土壤温湿度及草皮块返青覆盖度的影响,研究结果表明：遮阳网覆盖堆体较自然地表日均土壤温度显著降低,同时各深度层极大延长冻结期,降水对土壤水分的补充效应延后,并造成堆放期水分大量损失;穿孔膜覆盖堆体较自然地表提高了土壤温度,阻碍了降水对土壤水分的补充,并造成堆放后土壤吸持水能力降低。遮阳网覆盖的草皮块返青覆盖度显著高于穿孔膜覆盖的返青覆盖度,堆放期日平均土壤温度>0 ℃的堆放日数与草皮块返青覆盖度的线性拟合较好。工程建设中应尽量缩短堆放时长,采用透水透气类覆盖材料,增加土壤与空气热量交换,以维持更长的冻结期,并适时补充水分,提高草皮块铺植的恢复成效。     

花岗岩风化料弃土快速堆填过程中不排水抗剪强度评估

沿海沿江城市地下开挖产生的工程渣土含泥量大、含水率高且较松散,主要运往渣土场进行堆填处置。由于产量巨大而处置场地有限,许多渣土场在运营过程中存在堆填速度快、缺乏排水设施、超高超库容堆填等问题,容易引发堆填体失稳事故。目前对于非饱和工程渣土堆体在快速堆填过程中的失稳机制认识尚不清晰,尤其是对这一过程中的高饱和度工程渣土强度增长规律缺乏足够的认识。以深圳红坳渣土场填料——花岗岩风化料(CDG)填土为研究对象,对不同初始饱和度土样进行三轴不排水不排气等向压缩和剪切试验,结果表明:非饱和CDG填土不排水抗剪强度随围压增大呈非线性增长,增长速率与试样初始饱和度密切相关;当土样压缩后的饱和度超过0.7,不排水强度随围压的增长速率显著降低。基于有效固结应力法的原理,结合Hilf孔压公式和修正剑桥模型,提出了一种工程渣土不排水抗剪强度估算方法,并通过与试验结果对比验证了该方法对初始饱和度高于0.6的CDG填土的适用性。利用该方法确定的不排水强度cu与正应力σn的关系可应用于高饱和度工程渣土快速堆填中的稳定性分析。