井筒及围岩应力,应变观测方法研究

采用最新研制的岩体应力、应变匹配传感器对西安立井煤柱开采引起的井筒附加应力特别是对井筒穿过断层附近产生的附加应力进行了较系统的观测，并对观测结果进行了分析和总结。     

川西北倒三角形断块东部区域强震带形成机制与地震活动特征

川西北倒三角形断块东部区域地处青藏高原东部边缘地带,地跨川西北高原及其与四川盆地过渡带的高山峡谷区,属我国著名的南北向地震带的中段,因其特定的大地构造环境和强烈的现代地壳构造运动,导致其在强大的近东西向构造应力场的驱动和平卧“A”字型控震构造体系的控制下,沿两侧边界断裂向东强力楔入,于“构造急剧收口带”之西侧形成了一个近SN向地跨三大构造单元的强震带,强震沿该带有规律的往返迁移和重复发生,且地震活动强弱具有较明显的分形特征。     

巫山县污水处理厂高填方地基湿化变形试验研究

结合巫山县污水处理厂高填方工程，选取压实粘性土样，在室内进行了接近实际应力路径下的“单线法”湿化变形试验，研究了土样在不同的压实度、固结压力和湿化历史下的湿化机理、湿化前后的应力．应变关系及强度变化规律。取得的湿化变形试验成果表明，湿化使土样的变形模量和强度均有所降低；湿化变形不仅包括湿化体应变，而且包括湿化偏应变；随着压实度的增加，湿化变形减小。试验成果为巫山县污水处理厂高填方地基的填筑设计、控制湿化变形的措施和附加压密措施提供了依据。     

红透山矿床变质岩系褶皱构造特征浅析

红透山式铜-锌矿床形成于太古代克拉通裂谷槽盆中海底火山喷发-沉积环境。因此，矿床的空间展布严格受特定的含矿岩系所控制。槽盆构造中的岩层褶皱构造最发育，矿床赋存在具多期褶皱构造叠加的大型同倾向形褶皱内，褶皱的层间虚脱是控矿有利构造空间，可以借此预测矿体侧伏方向及赋存部位。     

静止环境中有阻力圆盘浮力射流特性的研究——(II)流场特性分析

在数值计算成果的基础上,对阻力圆盘浮力射流的流场进行了分析和总结,基于轴线流速的变化规律将盘后流场分为3个区域:回流区、过渡区和自相似区。得到了回流区的长度随弗劳德数F0、孔口直径D/d以及盘离孔口的距离H/d的变化规律,并得到了工况为H/D=1,D/d=2,6和H/D=3,D/d=2在不同弗劳德数F0条件下的横截面上的流速分布和达到自相似区的最小长度;结果表明弗劳德数F0的大小是决定绕流流态的主要因素;同时分析了由正常绕流发展到非正常绕流的压力场变化,发现由于弗劳德数F0的增大而导致流场中出现的第三个负压中心的大小和位置与绕流是否能正常发生存在密切的关系。     

沉降-时间曲线呈“S”型的证明及其应用——从土体本构关系

从土体本构关系出发,严格证明了在线性加载或近似线性加载情况下(这和岩土工程实际加载相类似),沉降-时间曲线呈“S”型,并由此建立了新的沉降-时间预测模型,工程应用证明了该模型的合理性。     

Proof of settlement-time curve appearing “S” shape with ramp load and its application base on stress-strain relationship

Based on stress-strain relationship of soil, the proof is made for that s-t curve appears “S” shape when the load is increased linearly, which is similar to construction process. A new model of forecasting the relation of settlement-time is presented. Case history shows the rationality of the method.     

某双向混凝土立交桥顶推法施工控制测量

文中所选立交桥为双向三车道桥梁,单幅为3跨105 m的箱型连续梁,重量3 400 t,横跨铁路线。对于跨铁路的桥梁建设,顶推法施工可最大限度地减少对交通的影响。桥梁重量大,所须牵引力约280 t,施工过程中对桥墩及其他建筑物产生的变形较大,施工前模拟施工状态,设计控制测量监控的基本方案,利用控制测量方法,对施工状态实时监测,预测变形及偏位、纠偏,使施工状态最大限度地接近理想状态。顶推到位后,轴向偏位满足1 cm的限差,桥墩变形基本满足施工规范的要求,最终顺利完成顶推过程。     

Compression limit state of HVAC submarine cables

An industry accepted standard does not currently exist for determination of compression limits in a subsea cable. This has resulted in most manufacturers specifying that subsea cables are not permitted to be axially loaded in compression.Additionally industry guidance does not exist regarding the consequences of inducing compression forces within subsea cables and the resulting effect on cable integrity. Industry recommended practice and guidance also does not have any information regarding experimental test arrangements to determine allowable compression levels within a subsea cable. This lack of modelling/testing guidance along with manufacturer recommendations of zero compressive loads within subsea cables results in overly conservative and restrictive design parameters for subsea cable installation and use.Due to the complex interaction within a subsea cable structure, such as contact interaction and friction between cable strands, theoretical modelling has been unable to provide reliable stress predictions and therefore an experimental testing regime is required if compression limits within the cable are to be appropriately determined. This paper describes combined axial and bending test arrangements that can be used as a guideline for determination of allowable compression limits for subsea cables.