安庆电厂碎石桩复合地基静载荷试验分析

探讨了在进行碎石桩复合地基静载荷试验时终止加载原则、复合地基承载力极限值的测定方法和复合地基承载力标准值的确定方法等问题。     

石砌体结构抗震抗剪强度理论的应用

本文基于石砌墙体的拟动力实验、工程实践及震害经验,经分析研究,提出石砌体结构的抗震设计强度验算及抗震设计方法,并结合实际工程计算,验证了本研究的可靠性与实用性。     

Exploration for dimensional stone — implications and examples from the Precambrian of southern Finland

Dimension stone is a natural rock that must fulfil high qualitative standards defined by both geology-based factors and non-geological factors. The stone itself (appearance/soundness) and the market demand are the two most important aspects in the quality assessment. The process of geological dimension stone exploration is a systematic and stepwise procedure, including individual steps of desk study, field mapping, detailed examination, geo-radar survey, and core drilling. The location of all economically feasible dimension stone deposits is strictly controlled by geological factors. Knowledge of these factors is fundamental in identifying new sites with potential for dimension stone. In this work the geological constraint on the occurrence of dimension stone in three areas, in the Precambrian of southern Finland, has been investigated. The deposits are localized to part of an area in which different geological features in combination have produced rock of good dimension stone quality. The study shows that, for example, vertical movements in the crust, magmatic evolution of an intrusion, and metamorphic grade define the location of rocks suitable for dimension stone.     

沉管挤密抗拔防浮碎石桩的抗拔承载力计算分析

基于现场试验检测结果,分析了沉管干振挤密抗拔防浮碎石桩在砂土中的抗拔破坏模式和应力传递机理,运用极限平衡原理研究了抗拔承载力,得到了极限抗拔承载力计算公式,并利用公式对工程实测结果进行了分析比较,表明两者较为一致。现场试验表明,未达破坏荷载前,抗拔碎石桩的抗拔承载力与变形有较明显的线性关系;抗拔碎石桩破坏性状明显,能明确得到抗拔碎石桩的破坏荷载。     

Nonlinear Behaviour of an Embankment on Floating Stone Columns

This paper describes a benchmark problem for a floating stone columns supported embankment. In the 3D model, a thick soft subsoil deposit represented by Singapore marine clay was treated by floating stone columns to support a 2.0 m high embankment. The 3D numerical results were compared among different constitutive models such as the hardening soil model, soft soil model, modified Cam-clay model and Mohr-Coulomb model, highlighting the effect of non-linearity in the overall performance of the ground structure. The advanced constitutive soil models allow more realistic soil response to be investigated. From the numerical results, the Mohr-Coulomb model with elastic-perfectly plastic stress-strain response was able to give comparable total settlements but failed to demonstrate some intrinsic behaviours obtained with advanced soil models. These intrinsic behaviours include the mode of failure, displacements profile, stress transfer mechanism and rate of consolidation. This benchmark example has given us an improved understanding of the performance of floating stone columns when a more realistic soil behaviour is modelled.     

寿山石的成矿地质条件和矿物组成

长期研究表明,寿山石的成矿地质条件主要受地层、构造、火山机构和火山成矿等综合作用控制。寿山石的矿物成分主要为地开石、高岭石和叶蜡石。因寿山石的成矿地质条件、矿物组成和产出部位的不同,形成色彩绚丽、命名异样、品种繁多、分类殊异。但通常以其成因、产状和历史传统分为田坑石、山坑石和水坑石三类。为便于识别、研究和讨论,将寿山石的主要品种及其特征一并简介。     

碎石桩加固饱和粉土地基的抗液化特性

除饱和砂土液化外,饱和粉土地震液化问题也是岩土地震工程中一个重要的研究课题。饱和粉土地基的地震液化及变形可以采用多种地基加固方法防治,碎石桩技术是常用方法之一。碎石桩复合地基的抗液化效应,主要是增加桩周土体的密度、利于桩体的排水以及由桩体分担地震水平剪应力（桩体减震作用）。但由于粉土的土质特性,粉土-碎石桩复合地基的抗液化特性与砂土有着明显的差异。本文结合目前国内外碎石桩复合地基抗液化研究的最新进展,对粉土-碎石桩的密实、排水减压和减震作用做了较详细的评述,最后提出了关于碎石柱复合地基抗液化特性需要进一步研究的问题。     

地震石从何而来——青川东河口地震遗迹地质公园

汶川地震后,一块名为地震石的巨石伫立在青川东河口地震遗迹地质公园里。对其来由,大家众说纷纭。通过实地调研,对其进行了显微鉴定,认为该石(蚀变辉绿玢岩)形成于海西—印支构造运动时期,并经后期的蚀变作用。在此次地震中,该石借王家山高速远程滑坡—碎屑流之力,最终抵达现在所处的位置。     

皖北灵璧磬云石的岩石学和地球化学研究

磬云石是产于灵璧地区震旦系张渠组地层中的一种微晶灰岩,以其色黑致密且敲击能发出青铜质的声音,而成为观赏名石和制作敲打乐器。磬云石主要矿物组成为微晶方解石,晶体自形程度较好,粒度均小于10μm,紧密镶嵌排列,富含有机质。在元素地球化学特征上,磬云石含有高的CaO含量,低的MgO、SiO2、Fe2O3、Al2O3含量,低的稀土元素含量,富集Sr、Cu、Mn、Ba等元素。通过与该套震旦系地层中产出的其他微晶灰岩对比研究表明,磬云石的矿物组成单一,颗粒大小均匀,颗粒排列紧密,颗粒间孔洞小且少,含有较高的有机质含量等特征,是其敲击能发出青铜质声音的主要原因。磬云石的形成与震旦纪时全球高的CO2浓度以及该区多发的地质事件有关,是震旦纪海水过饱和CaCO3的沉积环境与该区复杂的地质事件联合作用的结果。     

探地雷达在淡水区浅水域的探测试验

通过堤防护岸水域抛石探测、水下砼格及碎石层探测、江边堆场滑坡水域探测三个案例,说明探地雷达在淡水区浅水域探测效果。重点分析了探测对象所处环境的电导率、介电常数和探测所采用天线频率对探测效果的影响。探地雷达填补了浅水域工程勘察空白,研究成果对非水域探地雷达探测与检测具有借鉴意义。