加强化工地质科技创新刍议

化工矿产地质队伍组建以来,科技工作曾获得一些成果,取得一定效益。随着地质勘查队伍企业化进程的加快,地质科技工作也出现一定的问题。现化工地质科技创新应着重做好:重点化工矿产资源成矿区带研究;重点矿种成矿理论及找矿方法的创新研究;老矿山、资源危机矿山外围及深部地质找矿工作、地质勘查技术方法研究;低品位、难利用资源的开发利用研究;加快地质工作信息化进程、开展对周边国家和地区化工矿产资源战略研究等工作。当前化工地质勘查队伍应深入贯彻落实《国务院关于加强地质工作的决定》,发挥优势,建设、壮大化工地质科技工作队伍,做好相关的工作,使化工地质科技创新发挥深远的作用。     

Assessment of the dynamic response of unreinforced masonry structures using a macroelement modeling approach

The seismic performance of unreinforced masonry structures is strongly associated with the interaction between in‐plane and out‐of‐plane mechanisms. The seismic response of these structures has been thoroughly investigated by means of experimental testing, analytical procedures, and computational approaches. Within the framework of the numerical simulations, models based on the finite element method provide a good prediction of the seismic performance of unreinforced masonry structures. However, they usually require a high computational cost and advanced user expertise to define appropriate mechanical properties and to interpret the numerical results. Because of these limitations, simplified models for practical applications have been developed during the last decades. Despite this, a great number of these models focus mostly on the evaluation of the in‐plane response, assuming box (or integral) behavior of the structure. In this paper, a simplified macroelement modeling approach is used to simulate the seismic response of 2 masonry prototypes taking into consideration the combined in‐plane and out‐of‐plane action. The numerical investigations were performed in the static and dynamic fields by using pushover analyses and nonlinear dynamic analyses respectively. The latter is a novel implementation of a model previously developed for static analysis. The results obtained from this study are in good agreement with those provided by a detailed nonlinear continuum FE approach, demonstrating the applicability of this macroelement model with a significant reduction of the computational cost.     

A numerical study on the cumulative out‐of‐plane damage to church masonry façades due to a sequence of strong ground motions

Seismic shocks occur sometimes as a sequence, close in space and time, of destructive events of comparable intensity. In these cases, a significant portion of the damage to historical buildings can be related with the cumulated damage on structures that become progressively more vulnerable. This research investigates the specific increase of damage determined by a sequence of strong ground motions, focusing the interest on the out‐of‐plane response of 2 church masonry façades. The dynamic analyses were performed by a specific rigid body and spring model RBSM, which only accounts for out‐of‐plane damage mechanisms. Two idealized models of façade, each made of 2 different masonry bonds, have been studied by applying various sequences of recorded accelerograms. The results highlighted a complex relationship between the spectral content of the seismic shocks and the characteristics of the structures that change in the course of the loading sequence due to the development of damage. The Housner spectral intensity proved to be a reliable scalar measure of the ground motion destructiveness for these façades. Moreover, when considering a design‐consistent accelerogram that causes a relevant damage pattern, ie, with a significant elongation of the effective first period of vibration, the numerical results indicated a possible spectral intensity threshold below which the occurrence of repeated seismic shocks, both before and after the reference design shock, can be considered as irrelevant. On the other hand, a catastrophic increase of damage should be expected when this threshold is overcome.     

浅层地震反射波法在石膏矿采空区调查中的应用

随着人们对地下矿产资源的过度开采,地下空间形成了较大区域的采空区。采空区出现后,其上覆岩层平衡条件被破坏,使得上覆岩层产生移动变形,直到破坏、塌落,导致地表建筑物变形、破坏,地表大面积下沉、凹陷,形成大面积的采空塌陷区。采空区的存在使矿山生产面临很大的安全问题。近年来,矿山采空区的危害越来越受到人们的重视,在采空区调查中,各种地球物理方法起到了重要的作用,国内外以往探测实践表明,较为常用的物探测量方法有:高密度电阻率法、瞬变电磁法、CSAMT法、浅层地震反射波法、放射性土壤氡气测量法等,但每种物探方法的应用均具有一定的条件,需要根据岩石物性特征、场地条件、探测深度、环境影响等因素选择合适的地球物理方法。地震反射波法具有抗干扰能力强、分辨率较高等优势,被较多应用于矿山采空区的调查中。该文以临沂市兰陵县某石膏矿采空区为例,采用浅层地震反射波法对该石膏矿采空区进行调查,通过对获得的地震剖面资料进行处理和解释,取得了较好的探测效果,其技术方法可为同类采空区的探测提供借鉴和指导。     

基于Web网页与PDF文档自动构建更新语言模型

提出了利用HTMLParser和PDFBox工具包来编程实现对Web网页文本内容自动提取和PDF文档格式的转换并这些数据进行处理来适合HTK语言建模工具的要求。最后通过实验证明了采用该方法可以较好地实现语言模型的自动更新从而适应识别对象不断变化,同时减少了识别过程中的集外词并提高了语言模型的性能。     

Distinguishing Carbonate Reservoir Pore Facies with Nuclear Magnetic Resonance Measurements

  Characterization of carbonate rocks may involve identifying the important pore types which are present. In the past, this task has required detailed petrographic analysis of many core samples. Here, we describe a method which uses nuclear magnetic resonance (NMR) measurements to reduce the amount of petrographic analysis needed for porosity typing of carbonate reservoir rocks. For a rock sample which has been measured with NMR, our method decomposes the log(T₂) spectrum into at most three Gaussian-shaped components and gives a set of nine parameters. Two characteristic quantities having geological significance are extracted from the nine parameters. Values of the two quantities are compared with a reference set, established from samples having both NMR and petrographic evaluations of porosity types. We use a Bayesian approach to the classification of the dominant porosity type. Tests of our method on 103 samples show a correct prediction in 60 to 90 percent of the samples. The lower success rate was obtained for samples with five porosity types from three fields; the higher success rate obtained with samples with three porosity types from one well. The use of geologically significant quantities extracted from the decomposition gives comparable success rate to those obtained using a standard, non-geological approach such as canonical variates.     

高频地质雷达在堤坝路面质量评价中的应用

高频地质雷达是一种新型的物探方法,在堤坝的质量评价中,取得了很多有价值的检测结果,如:界面的起伏判定,界面间的接触空隙过大,“唧浆(水)”等。这为物探拓展应用领域提供了很好的实例。     

深基坑底板地层压力注浆设计与施工实践

结合常德市第一人民医院门急医技大楼的工程实际，介绍了深基坑底板地层压力注浆的机理，探讨了设计过程中几个主要参数的取值，指出了压力注浆的施工方法。     

导向钻进在复杂场地条件下长距离铺管工程中的应用研究

通过对长沙市某工程复杂场地条件下长距离非开挖导向钻进技术的应用研究，提出在类似场地条件下施工应尽量全面收集施工场地已有管线及地下构筑物资料；根据场地条件合理设计导向孔轨迹；配制钻进泥浆并合理选择泥浆添加剂；选择适合长距离拖管的拖管组件。     

GIS空间分析模型的建立

GIS的发展已有了30年的历史,在此期间人们的注意力多集中于空间数据结构及计算机制图方面,有关空间分析的问题尚不突出,但在今天,对于空间数据结构的研究已相对成熟,计算机制产了达到了实用化水平,实用的软件以及实际的系统均有计多成功的实例,因此系统的空间的空间分析功能就成为人们倍加关注的热点,可以认为,GIS的发展已从数据库型GIS进入分析型GIS的阶段。本文正是基于此,对空间分析的方法作了理论上的探讨,提出了按处理对象（图像,数据,事件）的不同来相应开发GIS软件的通用型,专用型空间分析模型,并分别采取“内嵌”或“外挂”的途径予以结合。最后以电力GIS中不同空间分析模型不同的建立方法为例,说明此咱分类方法可有效的解决时间,资金与人力资源的矛盾,具有很高的实用价值。