无损检测技术在边坡锚固工程质量验收中的应用

锚索加固技术广泛应用于岩土加固工程的各个领域,锚索的长度及灌浆饱满度是否达到设计要求是其评价锚固效果好坏的重要指标.目前,声频应力波无损检测技术是主要的锚固质量无损检测手段.结合汕昆高速公路贵州境内板坝至江底段边坡锚固工程质量检测试验,阐述应力波在锚索锚固工程质量检测中的应用原理,为无损检测技术应用于边坡锚索锚固质量检测提供经验和参考.     

边坡锚索无损检测技术及应用

预应力锚索广泛用于公路边坡加固。作为主动加固结构,预应力锚索直接关系到边坡的安全稳定。迄今为止,锚索锚固质量还没有有效的检测手段。采用应力波反射法,建立锚索锚固质量无损检测的理论基础,介绍AD-10锚索无损检测仪的硬件组成和工作性能,总结提出现场检测流程。以云南蒙新高速公路为例,采用锚索无损检测技术,成功用于锚索锚固质量检测、评价与监测。     

一种新型锚固结构—安全型压力分散锚索简介

压力分散型锚索的外锚头一旦产生变形,将导致各级钢绞线应力分布不均而使锚索失效,且压力分散型锚索不能进行极限承载力试验.通过在内锚固段设置可滑动的内锚具,开发出一种新型锚固结构—安全型压力分散锚索,使上述问题得到有效解决.安全型压力分散锚索是一种安全可靠的预应力锚固结构,值得在各类岩土锚固工程中推广应用.     

压力分散型锚索在高边坡加固中的设计实践

边坡加固技术是工程界一直关注的重要课题,边坡开挖后坡体内应力调整和位移变化的复杂性,对加固技术有了新的要求,而在此方面国内起步较晚,且多数采用集中拉力型锚索对岩体实施预应力。经过大量试验结果表明,在破碎岩体中,当锚索长度大于8～10m后,拉力型锚索的承载力无法获取较高的锚固力,而压力分散型锚索的受力性能不仅合理,而且在这种地层中可以实现较大的承载力。文章在分析拉力型锚索与压力分散型锚索锚固机理的基础上,结合沪蓉西高速公路宜昌段魏家洲桥基边坡加固工程,介绍了压力分散型锚索的设计计算方法。     

压力分散型锚索在高边坡锚固工程中的应用

介绍压力分散型锚索结构形式,应用现场环境、效果,着重说明张拉准备中差异荷载补偿张拉等情况,突出试验孔检测方法、要求,认为压力分散型锚索适用于地层结构岩性较差、土层覆盖较厚的边坡。     

拉压复合分散型预应力锚索在富水类土质高边坡锚固工程中的应用与施工

厦蓉高速公路(龙岩市境)改扩建工程K155+050左侧路基边坡为富水类土质复杂地质9级深路堑高边坡,采用多级锚索框架梁配合抗滑桩、路堑挡墙防护。富水类土质岩土体能够提供的摩阻力较小,普通压力分散型锚索应力分布不均匀,锚固段利用率偏低、锚固效果差。基于上述背景,本文提出富水类土质地层锚固采用拉压复合分散型锚索结构,可有效改善压力分散型锚索锚固段应力分布状态,通过合理的施工工艺、精细化施工过程取得良好工程效果,其应用及施工工艺可为今后类似高边坡的设计与施工提供一定的经验借鉴。     

压力分散型锚索施工中关键技术探讨

压力分散型锚索可以有效调用地层强度,显著提高锚索的承载力,对于滑坡治理具有较好的效果。该文结合工程实例,探讨了该类锚索的传力机制,对施工过程中的压力分散型锚索杆体制作方法、张拉方法和锚头防护等关键技术进行分析介绍。     

浅谈压力分散型锚索的张拉施工

随着公路、铁路、大型水(火)电站、厂房等的建设延伸向山地、丘陵地区,边坡越来越高,地质情况越来越复杂,大预应力锚固工程应运而生。而压力分散型锚索以其优越的力学性能和耐久性受到广泛关注。通过对压力分散型锚索张拉施工的分析,浅析压力分散型锚索的受力特点及优点。     

压力分散型锚索在岩质边坡处治中的应用

对河南省宛坪高速公路45 m高的边坡进行稳定分析,采用了压力分散型锚索和格构梁进行支护.压力分散型锚索是由若干个单元锚索组成,该类锚索可以有效调用地层强度,显著提高锚索的承载力.在锚头处安装12个锚索内力测力计,观测结果表明支护效果良好.     

预应力锚索在高速公路高边坡防护中的应用

压力分散型回收式锚索由若干个单元锚索组成,该类锚索可以充分调用工程地质体或构筑物自身潜在的稳定性并改善其内部应力状态,显著提高锚索的承载力,并能在其使用功能完成后实现对锚索体的全部回收。文中通过现场试验,对该类锚索的传力机制和工作特性进行了研究,并对其设计方法与施工工艺进行了探讨。     

轮胎压力监控器

轮胎压力监控（TPM）系统可以提高汽车安全性，并帮助驾驶员保持汽车轮胎的良好状态。状态良好的轮胎可保证汽车的安全性、性能和经济性。同时对降低维修成本产生间接影响。[编者按]     

挡土墙被动土压力破裂线及土压力分布变分解

为求解挡土墙被动土压力破裂曲线和土压力分布,取墙后填土的水平微分单元为研究对象,根据水平方向和竖直方向的力平衡以及力矩平衡,推导出基本微分方程。再通过求解出土压力分布表达式,推导出总的土压力泛函,利用欧拉方程求解泛函极值,其极大值就是被动土压力,极值曲线即是土体的破裂曲线。最后,利用基本求解思路,提出了挡土墙光滑情况下的滑裂曲线及土压力分布形式。     

缺气行驶是爆胎的祸根

车祸猛于虎!车辆在高速行驶时所发生的爆胎事故,往往会使驾驶员失去对车辆的控制,因而造成的事故是惨烈的,损失是严重的.     

非接触式胎压安全报警系统的研究

在现代汽车上,轮胎气压对汽车的安全性、舒适性、经济性以及操纵稳定性都有非常大的影响. 为了能更好地对轮胎气压起到更准确的监控,笔者在对已有的类似系统进行了简单介绍后,通过半径比较法和频率修正法设计研究了一种非接触式胎压安全报警系统.最后采用了一个应用实例,说明了该系统的实用性和科学性.     

高比压轴承的设计研究

本文通过对特殊用途高强化柴油机连杆衬套、连杆轴承和主轴承的设计、计算和试验研究,阐明了柴油机高比压轴承的设计特点,以及为保证轴承工作的可靠性,防止轴承早期失效所应采取的对策。     

非接触式胎压安全报警系统的研究

在现代汽车上,轮胎气压对汽车的安全性、舒适性、经济性以及操纵稳定性都有非常大的影响。为了能更好地对轮胎气压起到更准确的监控,笔者在对已有的类似系统进行了简单介绍后,通过半径比较法和频率修正法设计研究了一种非接触式胎压安全报警系统。最后采用了一个应用实例,说明了该系统的实用性和科学性。     

An optical tire contact pressure test bench

An optical tire contact pressure test bench developed by the IMMa group is described. The measurement system is based on the frustration of total internal reflection (FTIR) of light. The test bench allows performing normal pressure distribution and patch contact shape measurements on passenger car tires. The system is based on the use of a laterally illuminated glass on which the tire leans. Between them a plastic interphase is located that will cause the FTIR of light. A video camera catches the formed shining image through the glass. The brightness level in each pixel of the image can be related to the existing normal pressure. The study of the contact patch provided by the bench makes it possible to characterize tire behaviour under different loading states, inflation pressure, tire defects and toe and camber angles. The bench incorporates a computerized load and control system of the tire operation parameters, an image acquisition module and a data acquisition system that allow monitoring and acting on the experimental variables of interest in the tests such as load on the tire and environmental conditions. A supporting mechanical system incorporated to the bench allows providing the tire with variable toe and camber angles. From the images obtained with this system, the maximum normal pressure points, total force, size and shape of the patch can be determined, which are related to the tire-use conditions. As an application example, results that show the patch size and shape under different load and tire inflation pressures are presented. A further application, which is the use of the system for the detection and study of defective tires is also presented.     

An optical tire contact pressure test bench

An optical tire contact pressure test bench developed by the IMMa group is described. The measurement system is based on the frustration of total internal reflection (FTIR) of light. The test bench allows performing normal pressure distribution and patch contact shape measurements on passenger car tires. The system is based on the use of a laterally illuminated glass on which the tire leans. Between them a plastic interphase is located that will cause the FTIR of light. A video camera catches the formed shining image through the glass. The brightness level in each pixel of the image can be related to the existing normal pressure. The study of the contact patch provided by the bench makes it possible to characterize tire behaviour under different loading states, inflation pressure, tire defects and toe and camber angles. The bench incorporates a computerized load and control system of the tire operation parameters, an image acquisition module and a data acquisition system that allow monitoring and acting on the experimental variables of interest in the tests such as load on the tire and environmental conditions. A supporting mechanical system incorporated to the bench allows providing the tire with variable toe and camber angles. From the images obtained with this system, the maximum normal pressure points, total force, size and shape of the patch can be determined, which are related to the tire-use conditions. As an application example, results that show the patch size and shape under different load and tire inflation pressures are presented. A further application, which is the use of the system for the detection and study of defective tires is also presented.     

车用轮胎压力与温度监测系统的研究

汽车胎压监视系统主要用于在汽车行驶时实时地对轮胎气压、温度进行自动监测,对轮胎漏气、气压异常高温进行报警。制动系统的性能与驾乘人员安全密切相关,因此制动气压的精准性是一个非常重要的问题。     

ABS气压调控特性的研究

汽车防抱制动系统(Antilock Braking System)简称ABS.ABS是一个反馈系统,它根据车轮的运动状态对制动压力实施调控,从而修正车轮的运动状态,使其趋于理想化.实践表明,车轮的滑移率控制在15%～20%时,纵向附着系数最大,可达到最大的制动力,同时横向附着系数也保持较大值,使汽车具有良好的抗侧滑能力.故车轮的滑移率控制在15%～20%时,具有良好的防抱死性能,使制动过程处于理想状态.