DESIGN SLOPE牺牲阳极阴极保护设计方法

海洋工程领域常用的牺牲阳极阴极保护设计法可能存在过度设计的问题。针对此问题,文章介绍了适用于无涂层结构物的DESIGN SLOPE牺牲阳极阴极保护设计法。首先,简述了阴极保护下结构物表面生成钙镁沉积层的机理,分析了结构物表面极化特性在设计寿命期内的变化情况;然后,结合牺牲阳极阴极保护系统等效电路,引出DESIGN SLOPE的概念,说明该设计方法的基本理论;最后,应用DESIGN SLOPE设计法完成某平台牺牲阳极阴极保护设计工作。该法能够避免牺牲阳极阴极保护过度设计,从而提高设计方案的经济性。

Reliability Design for Longitudinal Slope Length of Expressway

The significance and the strategies of applying the reliability design method of longitudinal slope length in expressway engineering were explored in this study.The objective is to offer insights that can be beneficial for designing longitudinal slope lengths in contemporary expressway projects,with a focus on enhancing their reliability and safety.

A new slope optimization design based on limit curve method

A new method is proposed for slope optimization design based on the limit curve method, where the slope is in the limit equilibrium state when the limit slope curve determined by the slip-line field theory and the slope intersect at the toe of the slope. Compared with the strength reduction (SR) method, finite element limit analysis method, and the SR method based on Davis algorithm, the new method is suitable for determining the slope stability and limit slope angle (LSA). The optimal slope shape is determined based on a series of slope heights and LSA values, which increases the LSA by 2.45°-11.14° and reduces an invalid overburden amount of rocks by 9.15%, compared with the space mechanics theory. The proposed method gives the objective quantification index of instability criterion, and results in a significant engineering economy.

Optimum Design of Highway Excavation Slope Angle: Evidence from Dawu Section of Jingzhu Highway

The optimum design of the highway excavation slope angle is one of the most important problems to the highway construction and to the slope improvement. The Dawu Section of Jingzhu (Beijing Zhuhai) Highway is taken as an example to illustrate the study method for excavation slope angle design. The analysis of the engineering condition from different angles with different factors shows that the stability of the slope is calculated by using residual pushing force and the Sarma method. Then the sensitive analysis of the slope stability is conducted by using residual pushing force method. Finally, the optimum angle of design is presented on the precondition of ensuring the whole stability of slope and the economic reasonability. The study results show that the most sensitive factors are the shear strength parameter and the seismic force, and that the optimum excavation slope angle is 60°.

Comprehensive evaluation of high-steep slope stability and optimal high-steep slope design by 3D physical modeling

High-steep slope stability and its optimal excavation design in Shuichang open pit iron mine were analyzed based on a large 3D physical simulation technique. An optimal excavation scheme with a relatively steeper slope angle was successfully implemented at the northwest wall between Nos. 4 and 5 exploration lines of Shuichang Iron Mine, taking into account the 3D scale effect. The phys-ico-mechanical properties of rock materials were obtained by laboratory tests conducted on sample cores from exploration drilling directly from the iron mine. A porous rock-like composite material was formed for the model, and the mechanical parameters of the material were assessed experimentally;specifically, the effect of water on the sample was quantitatively determined. We adopted an experimental setup using stiff modular applied static loading to carry out a visual excavation of the slope at a random depth. The setup was equipped with acous-tic emission （AE） sensors, and the experiments were monitored by crack optical acquirement, ground penetrating radar, and close-field pho-togrammetry to investigate the mechanisms of rock-mass destabilization in the high-steep slope. For the complex study area, the model re-sults indicated a clear correlation between the model＇s destabilization resulting from slope excavation and the collected monitoring informa-tion. During the model simulation, the overall angle of the slope increased by 1-6 degrees in different sections. Dramatically, the modeled excavation scheme saved over 80 million tons of rock from extraction, generating enormous economic and ecological benefits.

A New Method of Construction of Robust Second Order Slope Rotatable Designs Using Pairwise Balanced Designs

The following article has been retracted due to the investigation of complaints received against it. Title: A New Method of Construction of Robust Second Order Slope Rotatable Designs Using Pairwise Balanced Designs. Authors: Bejjam Re. Victorbabu, Kottapalli Rajyalakshmi.The paper is a copy of Dr. Rabindra Nath Das’s former article, entitled “Slope rotatability with correlated errors (Vol. 54, pp. 57-70, 2003)” and “Robust second order rotatable designs (Part I)”. The scientific community takes a very strong view on this matter and we treat all unethical behavior such as plagiarism seriously. This paper published in OJSVol.2 No.3, 319-327, 2012, has been removed from this site.

A comparative study of pseudo-static slope stability analysis using different design codes

Many researchers have developed new calculation methods to analyze seismic slope stability problems, but the conventional pseudo-static method is still widely used in engineering design due to its simplicity. Based on the Technical Code for Building Slope Engineering（GB 50330-2013） of China and the Guidelines for Evaluating and Mitigating Seismic Hazards in California（SP117）, a comparative study on the pseudo-static method was performed. The results indicate that the largest difference between these two design codes lies in determination of the seismic equivalence reduction factor( f;). The GB 50330-2013 code specifies a single value for f;of 0.25. In SP117, numerous factors,such as magnitude and distance, are considered in determining f;. Two case studies show that the types of slope stability status evaluated by SP117 are in agreement with those evaluated by the seismic time-history stability analysis and Newmark displacement analysis. The factors of safety evaluated by SP117 can be used in practice for safe design. However, the factors of safety evaluated by GB 50330-2013 are risky for slope seismic design.

Geotechnical Approach for Slope Design and Management Strategy for Nchanga Open Pit,Zambia

Rock slope stability is a very important research area for many geo-engineers concerned with civil or mining works.Slope stability of pits,roads,tailings dams and other embankments is very cardinal as it directly impacts on the working or utilization of these facilities.After a spate slope failures at the Nchanga Open Pits,a challenge arose to investigate the design parameters that have been in use.This research

边坡支护工程设计和施工阶段关键技术分析

工程项目在进行建设过程中,不可避免地会出现开挖情况,对于地质较差的地方,为减小开挖工作量,常设置相关边坡防护措施进行及时防护。而边坡的防护形式和措施较多,其应用条件和经济性均不一致,若不进行相关现场分析和评估,盲目采用过大的防护,容易造成经济浪费,因此如何根据设计过程中的数据采用贴合的边坡防护是施工所希望达到的目的。本文以娄底市某边坡工程开挖为例,结合当地场地条件,分别从设计和施工角度对其在项目进行中的关键性技术进行分析,从而提出相关解决方案,达到经济适用性目的。最终结果证明,在施工完成后,该边坡情况良好。拟为相关类似工程提供参考。

滑坡治理方案的计算机辅助设计系统(Slope-CAD)的开发与研究

本文简要地介绍了“滑坡治理方案的计算机辅助设计系统 (Slope- CAD version 1.0 )”总体框架、基本思路、基本操作步骤以及其主要功能。滑坡治理方案的计算机辅助设计系统 (Slope- CAD)采用面向对象的程序设计语言和交互式图形处理技术开发。该系统具有交互式建立滑坡体地质模型、对滑坡体进行自动条分、自动采集各条块稳定性计算时所需参数以及智能化配筋等特点。利用 Slope- CAD,可以轻易地完成从滑坡体地质模型的建立→滑坡体稳定性计算→治理方案设计整个工作流程。通过对多个滑坡实例检验结果表明 ,Slope- CAD具有建模简单 ,操作方便 ,集成化程度高 ,自动化和智能化程度高 ,分析计算结果可靠 ,输出设计图纸方便快捷等优点 ,具有较大的推广应用价值。

建宁县某水厂边坡支护与排水设计

依托于建宁县某新建水厂边坡支护工程,采用动态设计法对场地的填方段边坡和挖方段边坡进行支护和排水设计,通过对安全性、施工难度、经济性、稳定性、效果等对比分析,最终选择挖方段边坡采用框架锚杆支护,而填方段边坡采用抗滑桩+锚索和挡土墙联合支护方案以及采用地表集水明排+坡体软式透水管或泄水管泄水的排水设计,采用极限平衡法验证了支护后的边坡稳定性。

巢湖市青苔山镁矿(冶镁白云岩)及冶金用白云岩矿矿山地质环境特征及治理建议

巢湖市青苔山镁矿(冶镁白云岩)及冶金用白云岩矿矿山生产造成地形地貌、生态景观破坏等一系列问题,急需进行生态修复工作。本文以现状调查为基础,以针对性解决矿山地质现状地质环境问题为重点,为矿山生态修复的治理提供更科学合理的治理设计方案。

长水机场隧道大坡度斜井反坡排水设计与施工技术研究

基于长水机场隧道,对其大坡度斜井反坡排水设计与施工进行了研究,根据现场抽排水需要,分阶段安装一级或多级泵站,以满足作业面排水。在1号、2号斜井开挖施工期间,采用集水坑接力抽排水方式;进入正洞后采用二级泵站抽排水,斜井中部缓坡位置水仓为二级泵站、正洞集水坑为一级泵站。斜井及正洞掌子面均设置临时集水坑及移动水箱。出口工作面施工段暗挖段里程为DK709+355~DK709+770,由大里程向小里程方向施工,顺坡排水,钻爆施工。实践证明,排水方案安全、合理、有效、可靠,没有因排水不及时或不能排水,对后续工程施工产生影响,提高了在大坡度斜井大流量反坡条件下隧道排水的施工水平。

基于应力水平的边坡加固设计方法研究

当前边坡优化设计较多的依赖于工程经验,尚缺乏理论层面的设计依据和指导体系,为此,提出一种将应力水平分布和稳定性分析相结合,综合确定边坡加固位置和规模的设计方法,通过3个顺层路堑边坡工程实例阐述了该方法的应用方式和效果。所得结论主要有:①基于应力水平确定加固位置、稳定性分析确定加固规模,这种综合性方法通常能得到较优的加固设计方案,既可为边坡的初步设计提供理论指导,也可为经验优化方案的校验提供理论依据;②对于顺层岩质边坡,在岩层分界面处应力水平往往较高,若开挖后岩层分界面有出露,采用锚索穿过岩层分界面提高坡体稳定性具有较好的效果;③“剥山皮”式开挖对稳定性帮助不大,对于此类边坡采用较陡的坡率挖除加固更有效。

高阿丁枫人工中龄林生长对坡向和密度的响应

为了解高阿丁枫人工林的生长过程,2021年对林龄21 a的高阿丁枫人工林进行每木检尺,以胸径作为标准木选择的依据,西南坡不同密度中各选择1株,南坡不同密度中各选择3株高阿丁枫标准木作为解析木,分析不同坡向和造林密度组合的林木生长差异。结果表明:林龄21 a时,不同坡向和造林密度组合的高阿丁枫林木的平均胸径、树高和材积分别为17.60~20.78 cm、25.73~28.51 m和0.3186~0.4293 m3,林木尚处于旺盛的生长阶段;处理组合间以上生长量均呈现极显著的差异。林龄1~9、1~10、8~16 a期间分别是胸径、树高和材积的速生期,其连年生长量最高分别达2.19 cm/a、2.74 m/a和4.3966×10^(-2)m^(3)/a。坡向、密度及其交互作用显著或极显著地影响高阿丁枫林木的生长。高阿丁枫隶属热区长寿命大径材树种,速生期延续较长,其生长对立地和密度较为敏感。优质高效的高阿丁枫人工林培育应选择最适宜的立地和造林密度,并且适时开展密度的动态调控。综上所述,造林密度通过影响树高生长从而影响材积生长,南坡采用3 m×2 m×5 m非均匀密度造林的单株总材积最大。研究结果可应用于生产实践中高阿丁枫优质高效人工林培育的立地选择和密度控制。

高边坡支护设计要点应用研究

从高边坡的地质岩层特性等方面分析了高边坡支护的特点,列举了高边坡支护中常见的支护方法,从岩土工程勘察、边坡稳定性计算分析、边坡开挖利用设计等层面,归纳了高边坡支护设计中的常见问题,提出应强化高边坡岩土工程勘察的精细化与全面化水平,科学选择边坡的典型截面与边坡稳定计算方法,并结合支护方式的适用条件与经济性,采用合理的支护方式加以组合,以提高高边坡支护的效果。

中欧(英)边坡极限状态设计方法差异研究

针对边坡极限状态设计问题,分别根据现行中、欧岩土设计标准,从极限状态设计标准体系、边坡可靠性分析方法、边坡极限状态设计方法等方面进行对比分析。结果表明:中、欧岩土工程设计的力学与数学原理基本一致,但相关标准的工程设计体系却存在显著差异;在边坡极限状态法的分项系数制定上,中国采用的水准Ⅱ方法较欧洲的历史经验法更为先进;中、欧边坡稳定性计算所采取的计算方法存在差异,进行铁路边坡极限状态设计算例对比无意义。

基于BIM的坡脚线确定及可视化研究

在机场、道路等大型基础设施建设的过程中,根据土体类型、按照一定的坡度直接放坡是边坡处理的常见方法之一。现有BIM软件的相关功能虽能在一定程度上满足坡脚线推算和边坡土方量统计的需求,但在机场地势优化设计的参数正向设计过程中,反复使用软件功能的时间成本较高,不利于最终方案的得出。针对该问题,本文提出一种坡脚线的推算方法,即通过建立坡面和地面的数学模型,依托Civil 3D平台进行二次开发,实现了坡脚线的自动生成及可视化。与已有的传统作图法及BIM的相关功能相比,其具有适合计算机求解、计算速度快等优点,在机场地势优化设计等需要多次建模求解的过程中具有较高的应用价值。

地下水运移对露天矿山边坡的影响探析与渗流减缓措施研究

地下水渗流劣化岩体力学性能,降低围岩稳定性,容易引发矿山边坡失稳。通过对某露天开采铁矿南帮边坡进行水文地质勘察,明确了地层渗透特性,分析了矿山边坡地下水分布特征和运移规律,并采用“帷幕注浆+降水井疏堵”的方式对地下水进行综合处置。研究表明,短时强降水入渗排土场形成蓄水体,然后以强风化构造裂隙发育岩层为渗流通道,由排土场向矿山采坑渗流,劣化岩体的力学性能,降低了土岩接触界面的抗剪强度,致使矿山边坡滑塌。现场实验表明,“帷幕注浆+降水井疏堵”方式对地下水的综合治理效果良好,有效截断了蓄水体与采坑之间的渗流通道,降低了地下水对矿山边坡的影响,提升了边坡稳定性,可有效解决矿区向下开挖延伸过程中的边坡滑塌隐患。

较软岩地段路堑高边坡施工安全技术应用研究

高边坡施工安全是项目管理中一项十分重要的工作,以西南区域某市政工程为背景,以技术价值创造服务安全生产为总体思路,在高边坡设计优化、高边坡开挖设备选型、防护工程安全管理3方面采取有效措施,形成可复制的高边坡施工管理经验,实现高边坡施工全过程安全、质量、进度均受控的目标,为同类型高边坡工程施工提供借鉴。