双峰县金坑冲金矿地质特征及找矿前景

本文概述了金坑冲金矿地质特征,并对其矿化规律作了总结。在此基础上,依据地质类比与土壤地球化学测量成果,指出王家湾一丫头山一带,是找石英脉一蚀变岩型金矿的远景区。     

深部气层和干层测井模糊综合评判

深部气层和干层的区分是常规测井解释的难题。认识始于实践。本文依据东濮凹陷深层试采资料,建立了两个模式各四个参数的隶属度曲线,进行气层和干层模糊综合评判研究,并用该地区深层试井资料作了检验,效果颇佳。证明模糊综合评判是区分深部气层和干层的一种行之有效的方法。     

聚苯乙烯轻质混合土的压缩变形特性试验研究

聚苯乙烯轻质混合土是一种新型的填土材料,国内对其压缩变形特性的试验研究较少。在无侧限抗压强度试验基础上,分析了聚苯乙烯轻质混合土的破坏应变、变形系数与抗压强度的关系;依据单向固结压缩试验,分析了不同配比条件混合土的压缩变形特性,得到压缩屈服应力和压缩模量,可为工程应用提供参考依据     

广州地铁小谷围岛站基坑支护设计与监测分析

依据地质条件与地形特点,对广州市小谷围岛地铁站基坑采用放坡土钉墙支护,部分地段采用超前钢管加强支护,盾构吊出井、调头井段采用钻孔灌注桩加内支撑支护方案。采用理正软件对不同设计剖面进行了理论计算分析。分析结果表明基坑安全可靠。依据有关规范制定了基坑施工监测方案,针对基坑工程施工监测结果进行了分析,可供同类工程借鉴。     

Element budgets of pine stands on lignite and pyrite containing mine soils

To analyze the development of pine ecosystems on lignite and pyrite containing mine soils, four pine stands with ages of 3–35 years were investigated in a chronosequence approach. Bulk precipitation, throughfall and soil solution in depths of 20, 40, 70 and 100 cm were studied over a three-year period to determine element fluxes in these forest ecosystems on extreme acidic and saline soils.Element budgets are controlled by the processes induced by pyrite oxidation such as intensive weathering of primary minerals, precipitation and leaching of secondary phases.Despite low water fluxes, element outputs can reach extraordinary high values due to very high concentrations in the soil solution. Although element outputs decrease drastically with stand age, respectively, site age, they exceed those of comparable pine stands on non-mine sites. Nitrogen release from the lignite fraction represents a special characteristic of the examined substrates. Nitrogen losses beneath the rooted zone can be 34 kg N ha⁻¹ yr⁻¹ in 100 cm depth. Element input and output in the examined ecosystems are far from balance. Closed cycling of nutrients seems to be recognizable in the case of potassium.     

评定渗流管涌公式

根据工程实际问题，推导了在江河堤围、深基坑开挖和矿山法地铁开挖三种情况下的评定渗流管涌公式，并指出应根据不同情况选用不同的评定渗流管涌公式，及使用中必须考虑的问题。     

太平煤矿深厚土层的水文地质工程地质性质

依据对太平煤矿3号煤区深厚土层的水文地质与工程地质勘测及室内外实验结果,分析了主要的水文地质与工程地质特征及其对3号煤开采的影响,对矿区防水煤岩柱留设高度进行了合理确定。     

强震作用下多层土质边坡破坏规律与变形特征

通过对汶川地震受灾区北川县陈家坝地区的地质灾害调查,根据现场松散土质边坡破坏情况,由工程地质类比法选择了计算模型和地震波,采用岩土弹塑性理论和FLAC3D软件分析了多层土质边坡在动荷载作用下边坡单元的剪切拉伸破坏和剪切应变动力响应规律。研究表明,在水平和竖直地震波联合作用下,地震边坡单元首先在坡体内产生剪切破坏。随着震动时间的增加,剪切破坏单元向坡脚和坡肩处延伸,而在坡肩处主要产生拉破坏,一旦剪切破坏面和拉破坏面贯通,将导致边坡失稳。强震过后边坡坡脚鼓出,坡肩下凹,整个坡体呈弧形破坏。     

高饱和度饱和土中爆炸波与结构的相互作用

利用改进的? 2.5 mm×5 m的模拟爆炸装置进行了一系列爆炸波与结构相互作用的实验,得出了爆炸波作用下结构上的表面压力、动量、应变的实测波形。实验结果表明,由于结构刚度较小,在相同爆心距离条件下结构的荷载与自由场的压力值相差不大;荷载在顶板的分布较为均匀,结构在爆炸载荷作用下发生整体变形,可以用中心荷载代替整体荷载;结构对爆炸波的反射,无论是弹性波还是冲击波,反射规律基本一致。随着饱和度的增大,结构上的反射系数和爆炸冲击波波速也随之增大。     

The First James K. Mitchell Lecture In situ soil testing: from mechanics to interpretation†

The current use of fundamental mechanics in developing rational interpretation methods for deriving soil properties from in situ test results is reviewed and evaluated. The focus is on some of the most widely used in situ test devices including cone penetrometers with and without pore pressure measurements (CPTU and CPT), self-boring and cone pressuremeters (SBPMT and CPMT), and flat dilatometers (DMT). In situ tests in both cohesive and frictional soils for measuring strength and stiffness properties, in situ state parameters, consolidation coefficients, stress history, and in situ stresses are considered in detail.