含夹层盐岩圆柱形储库力学特性的理论解析

Salt caverns are created by the method that circulating fresh water into the salt formation to dissolve the salt,so the cavern?s ratio of radius to height is small and the cavern can be simplified into a hollow cylinder. The intermediate zone of the cavern was sectioned to take as research object. Considering the fact that the salt deposit in China is characterized by more interlayer,an equivalent calculation model was established to discuss the stress distribution function near the layer,based on the method of equivalent relative displacement on contact surface between rock salt and interlayer and actual state. Where assuming the contact surface is smooth,and thus the elasticity solutions of the thick-walled cylinder could be used to calculate stress distribution,then local internal pressure near the interlayer are increased and decreased to adjust the relative displacement until equivalent to actual state. The contrast between the numerical simulation and analytic solution shows that two results on stress distribution considering effect of interlayer is basically the same,in which maximum error of radial stress ?r and circumferential stresson cavity surface are less than 6.8% and 2.7% respectively. The analytic result meets require of storage cavern design analysis.     

基于星间链路技术的GEO卫星定轨精度分析

地球静止轨道(GEO)卫星具有对地静止的特性,GEO 卫星应用日益增多,在高分辨率对地观测、气象、通信等领域都发挥着越来越重要的作用,对其轨道确定的需求也越来越高,研究GEO卫星的高精度定轨技术迫在眉睫。传统方法中利用地面站对GEO卫星实现实时自主定轨存在系统误差大、观测几何差等问题,导致星地测量的误差在定轨过程中被放大的倍数急剧增加,影响了GEO卫星定轨精度的提高。利用GPS卫星实现对GEO卫星的定轨时存在可见GPS卫星数量少,接收到的信号微弱,测量精度不够的问题。星间链路具有对GEO卫星观测几何好、测量精度高的优点,为GEO卫星定轨开辟了新思路。针对在星间链路资源有限情况下如何选择MEO卫星组合与GEO卫星进行建链的问题,以星间链路构型的PDOP值为优化指标,对MEO卫星对PDOP值的影响进行了分析,提出了遍历选星、直接选星、迭代选星三种链路资源配置策略,确定与GEO卫星进行建链观测的MEO卫星组合,并用仿真方法对三种算法进行验证,结果表明,提出的迭代选星的链路资源配置策略,能将GEO卫星的定轨精度维持在7~40m以内,同时将星间链路的使用效率提高5~120倍。     

灌浆岩石锚杆 拉拔变形和刚度的理论解析

岩石锚杆的变形计算是锚固工程设计中的一个关键因素。基于协调剪切变形段锚杆和岩体间剪切变形刚度的线性假定,不协调剪切变形段锚杆和岩体间剪应力沿杆长呈幂函数型分布的假定,通过荷载传递微分方程,对全灌浆锚杆和有自由端灌浆锚杆的拉拔变形和刚度进行了理论分析,推导出沿杆长剪应力分布函数、轴力分布函数和位移分布函数,进而可获得锚杆最大拉拔力和拉拔荷载–位移曲线。根据剪滞理论,由灌浆锚杆周围岩体单元应力平衡微分方程,推导出 锚杆与岩体之间剪切弹性变形刚度 的计算公式。与其它理论结果比较,表明本分析方法是合理的、可行的, 对于灌浆锚杆变形、刚度及强度设计具有参考价值。