碎石桩加固高填方地基的试验效果分析

碎石桩作为处理软弱地基土的一种有效手段，往往需要对其试验效果进行分析。评价碎石桩处理后复合地基的性状是否达到地基处理考核指标，并提出可能调整的方案。论文以四川九寨一黄龙机场高填方地基处理工程为背景，介绍了碎石桩法加固软弱土层的现场试验，并对碎石桩处理后复合地基的加固效果进行了检测分析。包括碎石桩体检测和桩间土检测，最后综合室内土工试验、动力触探测试及载荷试验检测结果得出，碎石桩对本工程软弱地基的处理能达到预期的加固效果。其复合地基承载力高于设计要求，具良好的导水性，能有效排出地基中地下水。目前，该试验成果已用于指导机场地基处理与高填方填筑体施工。同时，它对于其它类似工程亦有借鉴意义。     

北京纺机厂高层住宅地基处理方案对比分析

根据设计条件,周围环境,对填土地基处理方案进行了对比分析,确定了合理的地基处理方案。经载荷试验检测和沉降观测说明：长短ＣＦＧ桩结合的复合地基是很有前途的地基处理方案。     

瞬态瑞利波技术在地基强夯质量检测中的应用效果

传统的地基加固效果的检测方法主要是采用原位测试方法,如标准贯入试验、载荷试验、动力触探试验等,总体来说,这些方法可较直观地掌握强夯地基处理效果,但是工作效率较低,对场地环境要求较多,且离散度较高,不能对地基处理效果进行整体评价。因此,完善一种快速有效的强夯地基质量检测方法十分必要。本文以园博园湿地工程为依托,对瞬态瑞利波检测方法进行了深入探讨,通过对本工程采集的大量的瑞利波资料处理、分析,并与原位测试成果进行对比研究,给出了瑞利波速度与原位试验数据之间的相关关系,研究了瑞利波技术在地基强夯质量检测中的应用效果。     

饱和软弱地基冲压处理试验研究

冲压处理饱和软弱地基是一种新型的软基处理方法,对于处理浅层固结硬壳层十分有效,应用于土基处理领域,特别适用于公路、场道的地基处理。以某大型工程的饱和软弱地基为例,在划分的试验区块进行冲压动力固结试验,试验过程中监测孔隙水压力并分析监测结果,提出了合理的施工参数和间歇周期。检测表明,处理后地基获得了良好的加固效果;冲压试验为工程提供了合理的施工方法和施工工艺,也为展开大面积施工提供了保证。     

吹填砂土地基的不同加固方法效果评价

某港口堆场地基由砂土吹填而成,地基承载力约为65kPa,为使地基达到150kPa的承载要求,必须对该吹填砂土地基进行处理。根据场区不同的地层条件、使用功能和地基强度,设计分别采用插板振冲、插板强夯、不插板强夯三种加固方法进行试验。试验检测结果表明,三种加固方法处理后的地基承载力均能满足设计,插排强夯效果最佳。     

高原机场冰碛土地基强夯处理及试验检测

以四川稻城亚丁机场土石方工程原地面地基处理后冲兴段为例,阐述高原冰碛土地基的强夯处理及效果检测。采用波速测试与动力触探试验相结合的检测方法,并以载荷试验结果作参照对比,评价强夯效果达到了设计要求。此联合检测的方法,对类似加固地基效果检测具有一定的参考价值。     

干振碎石桩加固液化地基试验研究

根据高速公路工程液化地基加固试验研究 ,对干振碎石桩加固液化地基的原理、效果、检验方法进行讨论。研究成果表明 ,干振碎石桩用于处理液化地基具有较大的优越性。处理后地基均消除了液化。瞬态瑞利波法具有快捷可靠的优点 ,可以在地基处理质量检测中推广使用。     

桩端土加固处理设计及检测方法的探讨

介绍了人工挖孔桩桩端土承载力不足进行旋喷桩处理的设计过程以及处理后检测过程中遇到的问题。桩端土处理设计可以遵循一般的地基处理设计方法和原则,并针对复合地基承载力检测和桩端土极限端阻力的检测中存在的差异和共同点,提出组合静载荷试验的思路和方法,并在工程中予以实施,并取得了较好的效果。     

高能级强夯法在石油化工项目处理湿陷性黄土中的应用

对甘肃董志石油化工项目中3 000～15 000 kN m能级强夯处理湿陷性黄土地基的设计、施工、检测进行系统全面的研究,其中12 000、15 000 kN m能级均为国内处理湿陷性黄土的最高能级。通过标准贯入试验、室内土工试验、静力触探试验、瑞利波试验、平板载荷试验对强夯加固效果进行综合检测,得出有效加固深度、湿陷性处理效果等结论,并提出适应该地区强夯法处理深度的经验公式,为湿陷性黄土地基处理设计、施工、检测提供参考     

青龙水电站厂房地基工程地质评价

通过对开挖揭示厂房地基所进行的物理力学性试验及建基面承载力检测成果,对厂房主机间地基进行了工程地质分析评价,提出了对局部受开挖影响区加强处理的地质建议。在此基础上,通过处理后检验评价,说明加强处理是合理可靠的。     

关于岩石坚固性系数的测定方法

岩石坚固性可视为岩石抵抗破坏的一种度量。本文介绍一些测定岩石坚固性系数的方法,诸如“点载荷法”、“捣碎法”以及“规则或不规则形状试样的试验”。论文最后对捣碎法的发展和应用进行了评述。     

微粉末油浸法在珠宝文物鉴定中的应用

微粉末油浸法主要用于微观研究,对样品进行结晶光学测试。本文提供几个检测实例：高色翡翠戒指、手镯,新石器时代玉斧,被称为“江川出土的古代手镯”,新类型“天然田黄石工艺品（斜绿泥石型）”,微晶含铬云母玉及“天然彩色玻璃石”;并以其他方法测试资料相互验证和补充,使结果更为准确可靠。     

地下水污染调查中水样有机组分分析质量控制

根据《地质矿产实验室测试质量管理规范》的要求,为保证地下水污染调查中样品的准确测定,需采取质量控制方法。文章阐述了地下水样品的前处理和测定过程的质量控制措施,建立了地下水有机组分分析过程的质量控制流程,确保其检测数据达到规范所允许的范围。     

Criteria of Acceptance for Constant Rate of Strain Consolidation Test for Tropical Cohesive Soil

In this study, the rapid consolidation equipment (RACE) was developed as an alternative device to the conventional consolidation test using Oedometer, consuming merely a few hours for the whole precedure to determine the consolidation characteristics of cohesive soil. RACE operates based on the constant rate of strain (CRS) consolidation theory, which is a continuous loading method of testing, requiring a good estimation of the loading rate such that it is ideal for the achievement of steady state condition during testing. The steady state condition is achieved when the c _v values from drained and undrained face of CRS converged with the c_v from Oedometer test. A slightly modification has been made on the normal constant rate of strain (CRS) test by proposing a direct back pressure system to the specimen using a tube to saturate the soil sample. This research has produced a set of criteria for determining the suitable rate for the rapid consolidation test based on the ratio of normalized strain rate, β, and proposed a new coefficient in terms of a ratio of β to clay fraction (CF), as a part of new criteria for testing a fine soil. Four types of sample were tested with different rates of strain using the RACE and their results were compared with those conducted using the Oedometer on the same soil type, from which fairly good agreements were evident in many specimens. It was found from the study that the minimum value of normalized strain rate, β, for the CRS test is 0.005 and for the u _a /σ _v ratio is suggested as 0.01. Also, the maximum β/CF for soils with clay friction lower and higher than 50 % are 0.008 and 0.001, respectively. The minimum β/CF value for both conditions is 0.0001.     

Potential impact of ash eruptions on dairy farms from a study of the effects on a farm in eastern Bay of Plenty,New Zealand; implications for hazard mitigation

This paper investigates the impact ash fall would have on dairy farming, based on a study of ‘Tulachard’, a dairy farming operation at Rerewhakaaitu, North Island, New Zealand. It includes analysis of the potential effects on the dairy shed and milking machine, electrical supply and distribution, water supply and distribution, tractors and other farm vehicles, farm buildings (haysheds, pump sheds, implement sheds, etc.), milk-tanker access to the farm and critical needs of dairy cows and farm to keep milking. One of the most vulnerable areas identified in the study was the cooling of milk at the milking shed, pending dairy tanker pick-up. The cooling system’s condenser is exposed to the atmosphere and falling ash would make it highly vulnerable. Laboratory testing with wet and dry ash was conducted to determine its resilience to ash ingestion. It was found to perform satisfactorily during dry testing, but during wet testing significant clogging/blocking of the condenser’s radiator occurred, dramatically reducing airflow through the condenser. Specific mitigation recommendations have been developed that include cleaning with compressed air and adapting farm management techniques to lessen usage of the condenser during an ash-fall event. Specific recommendations for management of dairy farm operation are given to mitigate the effects of an ash-fall event.

MnHCF/MnO_2 Core-shell Nanostructures as Cathode Material for Supercapacitors with High Energy Density

A nanocomposite of manganese dioxide coated manganese hexacyanoferrate was synthesized by a facile co-precipitation method and tested as active electrode material for an electrochemical supercapacitor. A way called "Deep electro-oxidation" was used to generate manganese dioxide coated layer for stabilizing the electrode material. The structure and ingredient of the resulting MnHCF/MnO2 composites were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and X-ray Photoelectron Spectroscopy. Electrochemical testing showed a capacitance of 225.6 F/g at a sweep rate of 5 mV/s within a voltage range of 1.3 V, and high energy density of 37.2 Wh/kg at a current density of 0.5 A/g in galvanostatic charge/discharge cycling. It is suggested that the two different components, manganese hexacyanoferrate core and manganese dioxide shell, lead to an integrated electrochemical behavior, and an enhanced capacitor. The electrochemical testing and corresponding XPS analysis also demonstrated that the manganese coordinated by cyanide groups via nitrogen atoms in MnHCF did not get involved in the charge storage process during potential cycles.     

WH-1型电镀金刚石钻头的研制及其在坚硬、致密和弱研磨性地层中的应用

本文阐述了电镀金刚石孕镶钻头的研制方法和原理。此种钻头适用于坚硬、致密、弱研磨性(即所谓打滑)地层的钻进。攻克“打滑地层”的途径是:(1)降低钻头胎体耐磨性,促使金刚石出刃;(2)改变钻头底唇形状,提高金刚石破碎岩石的比压,增多孔底破碎岩石的自由面,使之易于破碎岩石。从4个钻探队、39个钻头的生产试验结果来看,上述研制工作既合理又有成效。     

页岩容量法等温吸附实验中异常现象分析

在容量法对页岩的等温吸附实验测试中,发现随压力增加吸附量呈现减小趋势,甚至出现负吸附量,测得的吸附常数Langmuir体积和Langmuir压力出现负值,与实际不相符,造成实验结果和吸附常数失去应用价值。从页岩吸附测试方法、吸附测试仪器等方面系统分析了容量法页岩吸附实验出现"倒吸"现象的原因;提出了实验中自由空间体积测试和吸附气含量计算存在的问题;并对页岩吸附实验方法和页岩吸附测试仪器提出相关建议。      

Quantifying and testing differences among means of compositional data suites

Commonly, geological studies compare mean values of two or more compositional data suites in order to determine if, how, and by how much they differ. Simple approaches for evaluating and statistically testing differences in mean values for open data fail for compositional (closed) data. A new parameter, an f-value, therefore has been developed, which correctly quantifies the differences among compositional mean values and allows testing those differences for statistical significance. In general, this parameter quantifies only therelative factor by which compositional variables differ across data suites; however for situations where, arguably, at least one component has neither increased nor decreased, anabsolute f-value can be computed. In situations where the compositional variables have undergone many perturbations, arguments based upon thef-values and the central limit theorem indicate that logratios of compositional variables should be normally distributed.