Dredged marine sediments used as novel supply of filling materials for road construction

The dredged marine sediments are classified as waste and how to deal with such kind of abandoned materials is a great challenge. The main objective of this experimental work is to provide a novel way to reuse dredged sediment as filling materials in road section. The laboratory dewatering test is performed to model the in situ evaporation and dewatering process of untreated and treated sediment with chemical binder. The impact of binder amount and time is discussed on the change of water content influenced by evaporation. To valorize dredged sediments as roadbed materials, a hydraulic binder is incorporated to investigate its effect on the bearing capacity and strength performance. The suitability of stabilized sediment is assessed based on the obtained mechanical results followed by a detailed discussion on the in situ test roads.     

A simplified 3 D.O.F. model of A FEM model for seismic analysis of a silo containing elastic material accounting for soil–structure interaction

The purpose of this study is the evaluation of dynamic behavior induced by seismic activity on a silo system, containing bulk material, with a soil foundation. The interaction effects between the silo and bulk material, as well as the effects produced between the foundation of the silo and the soil, were taken into account. Proposed simplified approximation, as well as the finite model, were used for analysis. The results, from the presented approximation, were compared with a more rigorous obtainment method. Initially, the produced simplified approximation, with elastic material assumption for the grain, could determine the pressures on the dynamic material along with displacements along the height of the silo wall and base shear force, etc., with remarkable precision. Some comparisons, via a change of soil and/or foundation conditions, were also made regarding the seismic pressure of the dynamic material pressure, displacement and base shear forces for both squat and slender silos. Comparing the analytical predictions to results from the numerical simulations produced good results. It can be concluded that the model can be used effectively to perform a broad suite of parametric studies, not only at the design stage but also as a reliable tool for predicting system behavior under the limit state of the system. The results and comprehensive analysis show that displacement effects and base shear forces generally decreased when soil was softer; however, soil structure interaction (SSI) did not have any considerable effects on squat silos and therefore need not be taken into practice.     

智利M_W8.8地震同震重力梯度变化

利用GFZ Release 05卫星重力GRACE观测数据,计算2010年2月27日智利MW8.8逆冲型地震的同震重力和重力梯度变化,分析其分布特征,可知:由GRACE探测到的同震重力变化在断层俯冲区域可达-9.5μGal,断层隆升区域可达+3.5μGal,结果与利用SNREI地球模型的位错理论计算的同震重力变化较一致,说明利用GFZ Release05 DDK5滤波数据,更能精确的反映同震重力场变化;GRACE检测的智利地震同震径向重力梯度变化Trr最大可达-600μE,位于发震断层东侧俯冲区域;通过对同震重力梯度分布特征分析,初步判断发生同震物质迁移的区域范围在断层俯冲区域为(67°—72°W,33°—38°S),在断层隆升区域为(73°—77°W,35°—39°S)。     

Recognition of shear heating on a long‐lived major fault using Raman carbonaceous material thermometry: implications for strength and displacement history of the MTL,SW Japan

The extent to which movement on major faults causes long term shear heating is a contentious issue and an important aspect in the debate about the strength of major faults in the crust. Comparing the results of experimental work on the kinetics of crystallization of carbonaceous material with results of thermal modeling show that the Raman carbonaceous material (CM) geothermometer is well suited to studying shear heating on geological time scales in suitable lithologies exposed around exhumed major fault zones. The Median Tectonic Line (MTL), SW Japan, is the largest on‐land fault in Japan with a length of > 800 km. Application of Raman CM thermometry to pelitic schist adjacent to the fault reveals the presence of a rise in peak temperature of around 60 °C over a distance of around 150 m perpendicular to the MTL fault plane. The spatial association of this thermal anomaly with the fault implies it is due to shear heating. Thermal modeling shows the recorded thermal anomaly and steep temperature gradient is compatible with very high rates of displacement over time scales of a few thousand years. However, the implied displacement rates lie outside those generally observed. An alternative explanation is that an originally broader thermal anomaly that developed during strike slip faulting was shortened due to the effects of normal faulting. Constraints on displacement rate, width of the original anomaly, duration of heating and peak temperature imply a coefficient of friction, μ, greater than 0.4.     

黔西南隐伏岩体圈定与金矿物源探讨

黔西南金矿勘查已升级至国家战略层面,弄清其成因机制具有重要意义。综合运用区域重磁资料,对区内深部基底物质进行研究,通过对浅、深部隐伏岩体圈定及地质-重力模型异常拟合计算,结合区域地质、矿产及化探资料,提出金矿成矿物源,主要有两种供给方式,一种为前人的由表层沉积岩提供矿源层,一种为本研究提出的由深部以中生代花岗岩或变质基底(含基性-超基性岩浆岩类参与)提供矿源层。厘定了12处浅部隐伏岩体异常区,分离出4大深部岩浆岩块体。研究成果基本反映了区内的客观地质现象和地质作用结果,为研究区金矿勘探提供相关依据。     

鄂尔多斯盆地铀富集分布的影响因素分析

前人研究成果分析表明,鄂尔多斯盆地石油主要富集于三叠系延长组和侏罗系地层,天然气主要为下古生界气藏,煤主要赋存于石炭系至侏罗系诸多地层。收集到的地质、测井资料和岩芯分析资料表明铀赋存于盆地奥陶系、石炭二叠系、三叠系、侏罗系及白垩系地层,铀在盆地深部和浅部地层赋存特征不同,深部地层的高自然伽马异常与铀丰度相关性显著。断裂构造存在证据和分布特征研究表明,鄂尔多斯盆地断裂构造发育,且对铀元素分布具有重要作用。本研究表明,盆地历经的构造运动和沉积环境变迁决定了多种矿产的赋存特征,盆地中油、气、煤对铀富集分布具有积极的促进作用。盆地内有机质丰度与铀异常关系密切。     

X射线荧光光谱用人工标准物质的研制

使用高纯物质人工合成的方法,成功研制了4个人工标准物质。该系列标准物质涵盖了钛、钒、锰、铬、钴、镍、铜、锌、砷、铅、铋、铷、锶、钇、锆、铌、钼、钨、钕、钽、铪、镱、锡、钡、铯、镓、锗、镧、铈等29个元素,不同分析元素的含量范围可扩大到0.00x%~8%。该系列标准物质不仅可以补充自然标准的不足,扩展校准曲线含量范围,而且能够修正干扰系数,解决了准确计算分析元素之间的干扰和仪器校正带来的实际困难。用4个人工标准物质取代单元素人工标准的配制方法,减少标准数量,节约了资源以及标准配制的时间,避免了X射线荧光光谱分析工作者的重复劳动,提高了工作效率。研制的4个标准物质经检验均匀性和稳定性良好,量值准确可靠,已被国家质量监督检验检疫总局批准为国家一级标准物质。     

东太平洋CC区多金属结核矿物学特征及物源

通过对东太平洋CC区洋底地质取样及实验测试分析,运用洋底照相、多频探测等多种地球物理方法手段,进一步阐明了CC区多金属结核的形态、主要类型、化学成分及分布特征.通过对CC区沉积作用、生物作用、洋底火山作用、海水化学成分、南极底流等因素的综合研究分析, 进一步揭示了多金属结核形成的物质来源.通过对CC区区域地质背景及地形地貌的综合研究分析, 进一步探讨了多金属结核的形成环境,并建立了成矿模式.