无定向导线的粗差检验

介绍了先求定向角γ和连接角δ,进而计算多边形内角和闭合差的粗差检验方法。通过大量实例证明这种方法是完全可靠的。     

带缓和曲线的特大桥坐标计算及放样方法

介绍一种带缓和曲线的特大桥桥墩在测量坐标系下的坐标计算及桥墩放样方法 ,以及Leica全站仪在桥梁施工放样中的应用     

松辽盆地白垩纪湖侵沉积层序与湖海沟通事件的地球化学记录

松辽白垩纪近海陆相盆地最大湖侵期的泉头组－嫩江组时期，可能发生了三次较大规模的海水入侵事件，时间分别为泉三、四段一青一段（阿尔布期），青二、三段顶部（土仑期）和嫩一、二段（晚桑托－早坎佩尼期）。海水注入使湖盆的水文地球化学和环境地球化学条件均发生改变，并在层序中留下沉积记录。海进期主要表现为：①重同位素组份增加，直至与同期海相层序的同位素组成相同；②介质的盐度指标（Ｓｒ／Ｂａ）、碱度指标（Ｃａ＋Ｍｇ）／（Ｓｉ＋Ａｌ）、还原性指标（Ｚｎ＋Ｎｉ）／Ｇａ和硫通量指标（Ｓ归一化含量）均系统增加。相反，海退期则上述指标显著降低。根据沉积层序的同位素组成、同期海水的同位素组成和同位素分馏的质量平衡关系，可求出研究层段内同位素的海水来源与淡水来源的比例（混合度）为０－５。并由此恢复出海平面升降曲线。     

起始方位角误差对附合导线平差结果的影响

附合导线是工程测量中最常见的布网形式.结合附合导线平差过程,文中用真误差分析方法推导了起始方位角误差对附合导线平差结果的影响公式;通过分析与数据计算,得到了起始方位角误差对平差后导线点坐标和导线边方位角的影响规律;并与测角误差影响进行比较,得出了起始方位角误差影响可忽略的条件,对导线测量的理论研究与生产实践具有参考意义.     

On bridges B(pL, qS) around triangular libration points

When μ is smaller than Routh’s critical value μ ₁ = 0.03852 . . . , two planar Lyapunov families around triangular libration points exist, with the names of long and short period families. There are periodic families which we call bridges connecting these two Lyapunov families. With μ increasing from 0 to 1, how these bridges evolve was studied. The interval (0,1) was divided into six subintervals (0, μ ₅), (μ ₅, μ ₄), (μ ₄, μ ₃), (μ ₃, μ ₂), (μ ₂, μ ₁), (μ ₁, 1), and in each subinterval the families B(pL, qS) were studied, along with the families B(qS, qS′). Especially in the interval (μ ₂, μ ₁), the conclusion that the bridges B(qS, qS′) do not exist was obtained. Connections between the short period family and the bridges B(kS, (k + 1)S) were also studied. With these studies, the structure of the web of periodic families around triangular libration points was enriched.     

水准网闭合差自动解算的新方法

介绍一种在水准测量中独立闭合环或附合路线自动搜索及闭合差自动解算的新方法。该方法将间接平差函数模型转化为条件平差函数模型,利用条件方程式的所有信息,搜索出独立闭合环或附合路线并快速解算出闭合差,与给定的限差进行比较,较好地检验并剔除粗差。最后经过编程实现该方法,用实例验证了该方法的正确性和用之进行观测值质量检核的有效性。     

全三维连片处理技术的应用研究

论述了全三维连片处理的基本方法,介绍了处理过程中相对相关技术的运用和研究     

围堰防渗墙与复合土工膜联接型式试验研究

防渗墙上接土工膜是围堰常用的防渗体系,两者变形是否协调是决定防渗成败的关键。以某围堰工程为例,通过围堰防渗体系中复合土工膜的受力分析和复合土工膜与砂砾料界面的直剪摩擦试验,研究了土工膜与填料之间的相互作用,提出了保证土工膜不被拉断应满足的条件。另外,通过离心模型试验监测复合土工膜在堰体与防渗墙变形过程中的应变,揭示了复合土工膜的受力性状和联接部位的破坏机制。结果表明,在一定上覆荷载作用下复合土工膜与堰体之间的摩阻力超过其所承受的拉伸力,导致预留伸缩节不能发挥作用;复合土工膜下部风化砂的固结变形使之与刚性防渗墙之间产生较大的差异沉降以及防渗墙与上游堰体的水平脱离,两种变形不协调均可导致与防渗墙联接部位的土工膜因受拉而破坏,在该基础上提出了改进的土工膜与防渗墙的联接型式和铺设方法。试验成果为指导围堰防渗体系的分析和设计提供了可靠的依据。     

Dynamic responses of two buildings connected by viscoelastic dampers under bidirectional earthquake excitations

In this study,dynamic responses of two buildings connected by viscoelastic dampers under bidirectional excitations are extensively investigated.The two buildings are a 10-story building and a 16-story building,with the shorter building on the left.Viscoelastic dampers are installed at all fl oors of the shorter building.Equations of motion are formulated using a fractional derivative model to represent the viscoelastic dampers.Three cases are considered with mass eccentricities at 0,10% and-10% with respect to the dimensions of the buildings.The responses of the buildings are numerically predicted at different damper properties.The simulation results indicated that the maximum horizontal responses of the buildings without eccentricities are signifi cantly mitigated.However,torsional effects are adversely increased.For asymmetric buildings,the effectiveness of the connecting dampers is affected by building eccentricities.As a result,mass eccentricities must be taken into account in damper selection.When compared with vibrations induced by unidirectional excitations,bidirectional excitations can increase the responses of coupled asymmetric buildings.In addition,installing dampers only at the top fl oor of the shorter building may cause a sudden change in lateral stiffness of the taller building.Consequently,the story shear envelopes of the taller building are changed.     

地铁隧道贯通测量方法的改进与精度分析

为了提高地铁隧道贯通测量的精度,本文提出了地面卫星定位控制网,采用城市CORS作为起算依据,联系测量采用悬吊三根钢丝的方法和双测站法来增加检核条件,隧道导线测量中加测陀螺边等改进措施,结合某市地铁工程实例,分析研究了观测结果,保证了地铁隧道贯通测量精度的提高。