箱涵顶进工艺在玄武湖水底交通隧道方案中的应用   总被引：2，自引：0，他引：2       下载免费PDF全文

王国权  罗国煜  李晓昭 《探矿工程》1998,(5):50-51

在玄武湖水底交通隧道筑堤开槽埋管方案中,为确保古城墙的安全,可采用箱涵顶进工艺穿越古城墙基础。介绍了箱涵顶进工艺的结构设计及实用前景。  相似文献   

大地电磁测深法在福建漳州地热区的应用   总被引：1，自引：0，他引：1  

吴广耀  曾陆海 《地球科学》1988,(3)

为了研究漳州地区深部构造和热源条件,在天宝、漳州、龙海一线进行了大地电磁测深测量工作。通过对大地电磁测深结果的分析和解释,表明在漳州地区龙海—浮宫一带上地幔高导基底明显上隆,在壳内10—13km深处具有明显的高导层,地表覆盖层电阻率很低。根据这些情况并结合地质资料推断,这一带地下存在着温度较高的热源及地下水补给条件,在地下水深循环和热对流良好的断裂交汇区,有可能形成水温较高的地热田。  相似文献   

米104盐井对接施工工艺实例     

王增海王永全  崔秀忠吴国强 《中国煤田地质》2007,19(A01):24-26

米104井位于陕西省榆林市米脂县，与米103井相距350m，设计对接靶点垂深2536．05m，造斜点垂深2330m．水平段124．79m。该井设计为三开井身结构，在施工中，根据不同的岩性采用了不同的的施工工艺及不同的钻井液。米104井钻进深度至2789m时，泥浆全部漏失，达到了一次对接成功。  相似文献   

The effect of increasing gravel cover on forest roads for reduced sediment delivery to stream crossings          下载免费PDF全文

Kristopher R. Brown  Kevin J. McGuire  W. Michael Aust  W. Cully Hession  C. Andrew Dolloff 《水文研究》2015,29(6):1129-1140

Direct sediment inputs from forest roads at stream crossings are a major concern for water quality and aquatic habitat. Legacy road–stream crossing approaches, or the section of road leading to the stream, may have poor water and grade control upon reopening, thus increasing the potential for negative impacts to water quality. Rainfall simulation experiments were conducted on the entire running surface area associated with six reopened stream crossing approaches in the south‐western Virginia Piedmont physiographic region, USA. Event‐based surface run‐off and associated total suspended solid (TSS) concentrations were compared among a succession of gravel surfacing treatments that represented increasing intensities of best management practice (BMP) implementation. The three treatments were no gravel (10–19% cover), low gravel (34–60% cover), and high gravel (50–99% cover). Increased field hydraulic conductivity was associated with maximized surface cover and ranged from 7.2 to 41.6, 11.9 to 46.3, and 16.0 to 58.6 mm h⁻¹ respectively for the no gravel, low gravel, and high gravel treatments. Median TSS concentration of surface run‐off for the no gravel treatment (2.84 g l⁻¹) was greater than low gravel (1.10 g l⁻¹) and high gravel (0.82 g l⁻¹) by factors of 2.6 and 3.5 respectively. Stream crossing approaches with 90–99% surface cover had TSS concentrations below 1 g l⁻¹. Reducing the length of road segments that drain directly to the stream can reduce the costs associated with gravel surfacing. This research demonstrates that judicious and low‐cost BMPs can ameliorate poor water control and soil erosion associated with reopening legacy roads. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

GPS近景交会定位技术在海岛礁测绘上的运用     

罗亮 《地理空间信息》2011,9(2):81-83,86

海岛礁测绘工程是国家测绘局"十一五"期间的5个重要项目之一,GPS近景交会定位模块是卫星快速定位信息采集系统的一部分.该技术可完成对海岛礁特殊地形的测绘任务,对困难海岸线的测绘提出新方法.  相似文献   

Generalized Averaging Principle and the Secular Evolution of Planet Crossing Orbits     

Giovanni Federico Gronchi 《Celestial Mechanics and Dynamical Astronomy》2002,83(1-4):97-120

Planet crossing orbits give rise to mathematical singularities that make it not possible to apply the classical averaging principle to study the qualitative evolution of Near Earth Asteroids (NEAs). Recently this principle has been generalized to deal with crossings in a mathematical model with the planets on circular coplanar orbits. More accuracy is needed to compute the averaged evolution of planet crossing orbits for different purposes: computing reliable crossing times for the averaged motion, writing more precise proper elements and frequencies for NEAs, etc. In this paper we present the generalization of the averaging principle using a model where the eccentricity and the inclination of the planets are taken into account.  相似文献   

反井施工技术在处理钻孔穿越坑道中的应用          下载免费PDF全文

李永超  罗永贵  王红阳 《探矿工程》2014,41(6):27-30

在危机矿山深部探矿钻探施工中,钻孔难免会遇到采掘或废弃的坑道,给钻孔的正常施工带来了诸多困难。遇此情况后,采用反井施工技术,对钻孔进行反拉扩孔实施套管隔离,会收到良好的效果。为此目的,设计了反拉扩孔钻具、解决了高泵压下循环介质的密封问题。实现了钻孔快捷、经济的一次穿越坑道,达到了地质设计的目的。  相似文献   

基于高斯平滑滤波的罗兰C周期识别新方法     

吴苗  李方能  苏晓庆  王国成 《海洋测绘》2013,(6):80-82

在有效估计天波延迟地波时间的基础上,提出了全新的基于高斯平滑滤波的罗兰C周期识别新方法。该方法完全摆脱了固定第三周期识别的思路,在有效防止信号出现周跳和确保接收机接收性能的精确性与稳定性的同时,提高了采样信号的信噪比,降低了信号电平的损失,增加了信息的利用率。  相似文献   

高位定向钻孔在上隅角瓦斯治理的研究应用     

彭冬  赵永哲  段会军  刘建林 《中国煤炭地质》2019,(4):38-41

为了有效解决上隅角瓦斯治理难题,以王家岭矿12318综放工作面为研究对象,基于关键层和"O"型圈理论,确定高位定向钻孔的合理层位。通过对比高位定向钻孔与穿层钻孔的抽采效果,试验表明:相较于普通穿层钻孔,高位定向钻孔有效孔段高达90%,辅助时间降低80%,抽采浓度提高50%,抽采纯量为穿层钻孔的4倍,上隅角瓦斯浓度降至0.31%～0.48%,降本增效显著,证明了高位定向钻孔替代普通穿层钻孔治理上隅角瓦斯的可行性和优越性。  相似文献   

工作面过空巷基本顶超前破断机制及控制技术     

刘畅  张俊文  杨增强  弓培林  王开  张小强  李玉琳 《岩土力学》2018,39(4):1411-1421

以工作面进入平行空巷、回撤通道时顶板超前破断、巷道被掩埋、支架压架的事故为研究对象,通过相似模拟试验对比了工作面过不同宽度空巷、充填与否时围岩破坏特征、应力变化和支架载荷变化,展现了工作面过大断面空巷基本顶超前破断及其灾变演化过程。研究表明：超前破断会导致基本顶一次性破断长度增加、上覆亚关键层同时破断。一旦发生超前破断,现有支护技术很难避免压架,故预防出现超前破断最为重要。鉴于此,运用Winkler地基梁理论对基本顶中弯矩和挠度进行了计算,解释了试验中围岩破断特征、支承应力和支架载荷的变化,给出了基本顶超前破断的机制：煤柱失稳是导致出现超前破断的主要因素,提高煤柱强度有利于预防超前破断。据此提出了局部注浆充填技术使煤柱由单轴压缩变为三轴压缩,提高煤柱支撑能力,并在现场实践中得到了验证。  相似文献