对交通隧道防排水原则的探讨

从保护地下水环境和隧道防排水的技术经济效果两个方面，阐述了隧道工程控制型防排水的必然性和必要性，并建议了两种模型。     

激光散斑法对预制缺口岩石的缝端微裂区变形过程研究

本文应用激光散斑法对预制缺口岩石的缝端微裂区进行了无接触位移测量,求得加裁点位移 d 和缝端张开位移η.通过对主裂缝的跟踪量测,表明该试件的裂缝在失稳前存在着亚临界扩展.在此阶段,预制裂缝缝端主裂缝的形式推测主要是类似“啮合”裂缝及部分张开裂缝,当缝端张开位移达到临界值时,荷载稍增,裂缝即快速扩展,以致发生断裂.     

二元光学波面变形器件的研究

基于计算全息原理设计了二元光学波面变形器件，一块二元光学器件的衍射效率比计算全息可提高４倍，高斯波面整形需要二块整形光学器件，二元光学器件的激光利用率比计算全息提高１６倍，而且制做工艺简单．     

免棱镜激光全站仪与fx-4800P计算器配合使用应用技术介绍

文章介绍京福高速公路南平段NLA1合同段堵兜隧道施工中免棱镜激光全站仪与fx-4800P计算器配合使用技术。     

关于用奇异函数求解阶梯形梁变形的两个问题

对于n段阶梯形梁,X_o=0,X_1,X_2,……,X_(n-1)为第一、第二、……、第n段梁左截面的坐标,J_1,J_2,.....,J_n为相应段梁的惯性矩。根据,先将梁惯性矩的倒数用阶梯函数表示:其中此时,梁的挠曲线微分方程为其中E为材料的弹性模量;M(X)为梁的弯矩,由奇异函数法求出。依据奇异函数的积分规则,由(3)式可分别得到梁的转角方程和挠度方程:     

隧道级联大功率半导体激光器热特性分析

基于光谱法，通过测量靠近衬底的有源区波长的变化来表征其温度的变化，计算了隧道级联多有源区大功率半导体激光器的热阻。与普通半导体激光器相比，随着有源区数目的增多该热阻有增大的趋势，但并没有成倍增加，主要原因是隧道级联半导体激光器的串连电阻没有成倍增加。     

浅谈下穿隧道结构防水施工方法

广州市轨道交通三号线洛溪车辆段及综合基地下穿隧道位于场坪基线JCK0 706.23～JCK0 734.03段,全长350m.下穿隧道主要在淤泥层中修建,且由于与珠江相距较近,地下水侧向补给丰富,技术难度大,对防水要求标准高.本文根据广州市轨道交通三号线洛溪车辆段及综合基地下穿隧道的施工实践,阐述防水设计、标准与要求、防水施工方法等.     

地铁隧道近距离下穿建筑物的保护

某城市地铁隧道在距某22层高的宿舍楼仅5.4m位置下穿通过,该楼为筏板基础,无桩基,基础埋深较浅,在与此楼如此近距离的施工过程中,减少对该楼的扰动,对该楼的保护成为一个技术难题.     

Damage and fracture evaluation of granular composite materials by digital image correlation method

This paper presents the applications of digital image correlation technique to the mesoscopic damage and fracture study of some granular based composite materials including steelfiber reinforced concrete, sandstone and crystal-polymer composite. The deformation fields of the composite materials resulted from stress localization were obtained by the correlation computation of the surface images with loading steps and thus the related damage prediction and fracture parameters were evaluated. The correlation searching could be performed either directly based on the gray levels of the digital images or from the wavelet transform (WT) coefficients of the transform spectrum. The latter was developed by the authors and showed higher resolution and sensitivity to the singularity detection. Because the displacement components came from the rough surfaces of the composite materials without any coats of gratings or fringes of optical interferometry, both surface profiles and the deformation fields of the composites were visualized which was helpful to compare each other to analyze the damage of those heterogeneous materials. The project supported by the National Natural Science Foundation of China (10125211 and 10072002), the Scientific Committee of Yunnan Province for the Program of Steel Fiber Reinforced Concrete, and the Institute of Chemical Materials, CAEP at Mianyang