客专32m双线后张法PC简支箱梁静载试验技术

通过介绍时速350km客运专线铁路无碴轨道双线后张法预应力混凝土简支箱梁静载试验过程,阐述了无碴轨道双线后张法预应力混凝土简支箱梁静载试验技术。     

客运专线减振型CRTSⅠ型板式无砟轨道凸形挡台设计计算研究

针对减振型CRTSⅠ型板式无砟轨道的凸形挡台进行受力分析和计算,考虑了列车荷载的纵向力、横向力即温度力等对凸形挡台的受力影响,并分别推导出了这些荷载影响因素对凸形挡台受力的计算公式。最后对减振型板式轨道的凸形挡台进行受力计算和结构设计,给出了凸形挡台的结构配筋方式。     

客运专线桥梁挠曲变形对CRTSⅠ型板式无砟轨道结构受力影响分析

对列车荷载通过桥梁而梁体发生挠曲变形时,CRTSⅠ型板式无砟轨道结构受到的附加挠曲力进行分析。首先推导了桥梁挠曲变形对无砟轨道结构受到的附加挠曲力的计算方法,然后分别对我国时速300～350km、200—250km的几种主要桥梁、上CRTSⅠ型板式无砟轨道的轨道板和底座板受到的附加挠曲力进行计算,为CRTSⅠ型板式无砟轨道的结构设计提供参考。     

关于防灾安全监控系统设计方案的探讨

防灾安全监控系统在我国铁路已成功应用。结合南宁至广州铁路工程,探讨关于防灾安全监控系统的设计方案。     

A Simplified Approach to Analysis of High—Rise Frame Tube Structures

Based on finite element method and finite strip method, a simplified approach was presented to analyze high-rise frame tube structures. The generalized strip element is introduced and then the generalized stiffness matrices for beam and column-line are derived by using the displacement functions that describe the nodal displace-ments and displacement transforms. Furthermore, the formulas for the generalized stiffness matrix of generalized strip element and load arrays corresponding to the displacement parameters were developed. It is shown through a series of numerical computation that the nodal angular displacements at the same floor in a generalized strip element are approximately identical. A comparison of the finite element method and the finite strip method shows that the simolified approach not only is accurate, but also reduces the number of basic unknown quantities.     

A PARALLEL SWITCH FABRIC BASED ON CROSSBAR

With the increase of link rate, the arbitrator of centralized switch fabric becomes too complicated to implement. A parallel switch fabric based on crossbar, named as PSFBC （Parallel Switch Fabric Based on Crossbar）, has been proposed in this paper. PSFBC is composed of k switches whose rate is 1/k of link, these switches exchange cells in parallel; this increases the arbitrator＇s period and make it easy to implement. Load is evenly distributed to each switch with FCFS （First Come First Serve） rule, it can keep the order of cells in one stream. A multi-class queue scheduling policy is used in PSFBC to ensure the quality of realtime streams. Experiments show that the load on each switch in PSFBC is well balanced, its average delay of cells is little and its performance is very close to centralized switch; and with the increase of number of parallel switches, the loss of PSFBC＇s performance keeps very small, it becomes easier to implement.     

THE EXPRESSION OF BCL-2, BAX AND CASPASE-3 IN NEURON OF THE SPINAL CORD ANTERIOR HORN AFTER CAUDA EQUINA ACUTE COMPRESSION

Objective To explore the influence of the acute cauda equina compression on the iumbosacral spinal cord; To clarify the pathologic change of the motor neuron after acute cauda equina compression. Methods 27 canis familiaris were randomly divided into 9 groups （3 in each） ： one for normal group, one for control group, and seven for compression groups. The control group and compressed groups was given operation and the sac made of silica gel was placed under the lamina of L5-6. Water was injected into the sac until their posterior legs paralysis in compressed groups, the animals had been compressed for 4, 8, 12, 24, 48, 72, 168 hours. The control group were not injected water. Cells apoptosis was investigated with the technology of TdT-mediated biotin dUTP nick end-labeling （TUNEL） staining. The Bcl-2 Bax and Caspase-3 protein was investigated by immunohistochemical method. Results TUNEL staining cells in anterior horn presented after compressed 8-12 hours, and at 72 hours the number of positive cells got to maximum, it decreased subsequently after 168 hours. The protein of Bax, Bcl-2 expressed a little in normal motor neuron. The caspase-3 protein didn＇t express in normal ceil. They all reached the peak at 72 hours after compression. Conclusion The apoptosis of motor neuron occurred earlier after eauda equina acute compression. Bax protein restrained Bcl-2 protein then active caspase-3 and conduced apoptosis of motor neuron.     

大直径钢管砼中核心砼轴压本构关系研究

对现有的钢管砼中核心砼的本构模型进行了数值分析;通过不同直径试件的轴压试验,分析了直径大小对模型的影响,得到了适合于大直径钢管砼的核心砼本构关系.     

Local Tensile Strength of Connection Between H-Steel Beam Flange and Concrete-Filled Circular Column Tube with Through Diaphragm

This paper focused on investigating local tensile strength of connection between steel beam flange and concrete-filled circular column tube with through diaphragm. Three specimens were designed and tested to failure,and the structure behavior was studied by experiment and FEM analysis. On the basis of the results obtained, an estimation for local plastic and ultimate strengths of the connections using yield line theory was attempted, which results in a good prediction.     

煤系地层采空区公路路堑高边坡的加固治理

以京珠高速公路粤境北段B标煤系地层采空区的杨梅山 (K16 +930～K17+2 6 0 )路堑高边坡治理工程为例 ,介绍钢筋砼人工挖孔抗滑桩、预应力锚索地梁等支挡结构 ,满铺浆砌片石护面墙、砼空心六菱块植草等坡面防护措施 ,结合排水、减载等多种工程手段综合治理高边坡的工作实践