高应变动测技术中波速确定方法的研究

本阐述了高应变动测技术中波速确定的主要方法，总结分析了它们在高应变动测技术中的缺点，并提出了一种利用高应变动测结果来确定桩波速的新方法。     

高应变动测和静载荷试验对比检测单桩承载力

对常德市钻孔灌注桩,利用高应变动测与静载荷试验相结合检测承载力,并对检测结果进行对比分析,为在本地区推广应用高应变动测新技术提供依据。     

基桩承载力动测中的辐射阻尼及其参数取值研究

基桩承载力动测技术的推广，为桩基础工程质量的提高起到了极大的推动作用。但动测技术在某些方面尚须认真积累经验才能得到完善。文章对基桩高应变拟合法承载力分析中的桩-土相互作用模型进行了阐述，并以烟台地区的测试经验为基础，结合工程实践，对辐射阻尼桩-土相互作用模型在灌注桩承载力分析中的应用以及参数取值进行了分析研究。     

基桩低应变动测的若干问题探讨

就目前基桩低应变动测中存在的若干技术问题提出了一些修正性看法，以期纠正庆变动测中存在的一些非科学观点。     

响水风电场试验桩动静对比分析

静载试验是确定桩基单桩承载力的可靠方法.高应变动测试桩因其经济、快速而得到广泛应用,但其误差来源比较多,在实际应用中需要与静载试验结果对比.通过响水风电场试验桩的动静对比研究,分析了高应变动测法的一些误差来源,并提出了工程桩的桩基检测建议.     

结构面量测最佳测线长度的确定

测线法是野外采集结构面几何特征参数的常用方法之一。为了保证采集的结构面样本数量足够多,同时又使测量工作量最省,测线法应用时首先需要确定一个能够保证测量精度的最小测线长度--最佳测线长度。当前研究人员一般通过结构面间距的概率特征确定最佳测线长度,研究成果表明,仅依据间距的概率特征确定的最佳测线长度往往偏小,在确定最佳测线长度时还需要考虑迹长等其它结构面几何参数的概率特征。在此基础上提出了一种确定最佳测线长度的修正方法,并结合两个具体的算例说明了修正方法的应用情况。     

功果桥水电站混凝土强度与声速专用测强曲线的建立与分析

混凝土强度与声波速度值有一定的比例关系,因此在现场检测中可以采用声波速度值推求混凝土强度值。由于各地区各工程混凝土浇筑时使用的砂石料和水泥不同,变化较大,因此声速(Vp)随着砂石料和水泥的变化而变化,特别是砂石料对Vp的影响更为明显。因此在全国范围内没有固定不变的强度~声速(Vp)曲线。为了更快捷地掌握工程的混凝土浇筑质量,需建立专用测强曲线。     

动测技术评价桩基质量的理论和实践

重点介绍反射技术评价桩基质量的理论和实用技术，并通过工程实例证明该法的有效性。     

跨孔对测孔斜校正矢量方法研究总结

跨孔对测法也叫穿透测试法，被广泛地应用于岩土工程波动勘测中。由于对测的双孔不平行会导致激振点与接收点间的穿透距离与孔口距离不一致，因此穿透距离应进行孔斜校正。当钻孔越深、孔口距离越近，这种由钻孔倾斜引起的穿透距离变化就越大，孔斜校正就越显得重要。本文在对现有孔斜校正方法总结与研究的基础上，提出钻孔倾斜校正矢量法，该法能对不同情况下的孔斜进行校正，弥补了现有各种校正方法的不足。     

曲线隧洞掘进方向测设的精确简便方法

本文介绍了隧洞掘进方向测设的简便方法的原理 ,并给出了示例     

SONIC SPEED AND SHOCK WAVE IN HIGH VELOCITY AERATED FLOWS FROM HIGH HEAD DISCHARGE STRUCTURES

1 .　INTRODUCTIONWiththedevelopmentofhydropowerstationsinChina ,highdamshavebeenbeingincreasinglybuilt .Alotofhighdamsthatisgreaterthan 10 0minheighthavebeensofarcompleted .Andmanysuperhighdamsover 2 0 0mhighsuchastheErtanandLontanHydropowerStationswerecompletedorareunderconstruction .Someofthemevenhavetheheightsoftheorderof 30 0msuchastheXi aowanandXiluoduoHydropowerStations .Ac cordingtoincompletestatistics ,nearly 30superhighdamsthatisgreaterthan 2 0 0minheighthavebeensofarcomplete…     

PROBABILITY DISTRIBUTION OF IN-LINE WAVE FORCES ON A PILE IN IRREGULAR WAVES

The probability distribution of in-line wave forces on a pile can bemathematically summed up to that of a theory and the assumption of wave period being constantare used and the above probability distribution is simplified to that of a single dimentsionfunction.The probability density functions of the peak values of total wave forces on a wholevertical pile in irregular waves are derived from that of wave height which is the Rayleighdistribution(deep water wave)or the Kerohovski distribution(shallow water waves)on the baseof the Morison Equation.The identification with experimental data shows that suchsimplification is successful.These distributions are compared with Weibull distribution andRayleigh distribution and the result shows that the shallow water distribution of wave forcesobtained here is the best one and can be used in practice.     

PHC-钢管组合桩高应变检测修正方法

针对PHC-钢管组合桩这类非常规桩的极限承载力设计及高应变检测难题,开展了高应变试验和竖向静载试验。设计制作3根不同长度组合的PHC-钢管组合桩,采用锤击法沉桩,通过高应变现场试验和竖向静载试验,得出基于两种试验数据的极限承载力;依据高应变和竖向静载试验结果,通过理论分析提出了PHC-钢管组合桩高应变实测曲线拟合法的修正方法。结果表明,对于PHC-钢管组合桩,高应变实测曲线拟合法得到的极限承载力大于竖向静载试验下的极限承载力,提出的修正方法计算结果与竖向静载试验结果基本一致,可用于PHC-钢管组合桩极限承载力高应变法检测。     

NON-LCL AND TRACER TEST FOR GROUNDWATER FLOW IN A SINGLE FRACTURE

1. INTRODUCTIONGround water movement in naturally fracturedmedia is highly complex duetothe strongly varyingvelocity fields . Acritical issueinthe discrete mod-el is the validity of the Darcian-type“LCL”. TheLCL, whichis represented by a linear relation…     

基桩测试技术及其应用

简要介绍基桩检测中反射波法、高应变凯司（Ｃａｓｅ）法和静载荷法的方法原理及其工程应用，并通过工程实践指出了基桩检测的方向。     

A NUMERICAL STUDY OF THE TRAIN-INDUCED UNSTEADY AIRFLOW IN A SUBWAY TUNNEL WITH NATURAL VENTILATION DUCTS USING THE DYNAMIC LAYERING METHOD

The objective of this study is to investigate numerically the characteristics of train-induced unsteady airflow in a subway tunnel with natural ventilation ducts. A three-dimensional numerical model using the dynamic layering method for the moving boundary of a train is first developed, and then it is validated against the model tunnel experimental data. With the tunnel and subway train geometries in the numerical model exactly the same as those in the model tunnel experimental test, but with the ventilation ducts being connected to the tunnel ceiling and a barrier placed at the tunnel outlet, the three-dimensional train-induced unsteady tunnel flows are numerically simulated. The computed distributions of the pressure and the air velocity in the tunnel as well as the time series of the mass flow rate at the ventilation ducts reveal the impact of the train motion on the exhaust and suction of the air through ventilation ducts and the effects of a barrier placed at the tunnel outlet on the duct ventilation performance. As the train approaches a ventilation duct, the air is pushed out of the tunnel through the duct. As the train passes the ventilation duct, the exhaust flow in the duct is changed rapidly to the suction flow. After the train passes the duct, the suction mass flow rate at the duct decreases with time since the air pressure at the opening of the duct is gradually recovered with time. A drastic change in the mass flow rate at a ventilation duct while a train passes the corresponding ventilation duct , causes a change in the exhaust mass flow rate at other ventilation ducts. Also, when a barrier is placed at the tunnel outlet, the air volume discharge rate at each ventilation duct is greatly increased, i.e., the barrier placed at the tunnel outlet can improve remarkably the ventilation performance through each duct.