Analysis of Highway Subgrade Slope Protection and Support Technologies

As an important transportation hub in China,the traffic volume and driving speed are important aspects of expressways.Therefore,the protection requirements for roadbed side slopes are higher,and it is necessary to resist rainwater erosion and other damages by protecting the side slopes.Therefore,it is necessary to adopt effective technical means of subgrade protection and support.This paper mainly summarizes the characteristics of highway subgrade slope protection construction and slope protection and support technologies.

Slope Protection with Vegetation of Baoji(Shaanxi)-Hanzhong(Shaanxi) Expressway

With expressway development and environment protection consciousness improving, slope protection technology with vegetation has drawn much more attention. From the perspective of ecology, Baoji-Hanzhong Expressway maximized slope protection technology with vegetation and formed attracting landscapes on basis of eco-protection. This research introduced the technology of Baoji-Hanzhong Expressway, and explored a low-cost and effective biological slopeprotection way, suitable for Baoji-Hanzhong Expressway, according to slope protection technologies, at home and abroad, with botany, water and soil conservation engineering, and architecture, which fixed and stabilized slopes, prevented rainfall scouring, and advanced slope protection development in China.

Root structure of slope protection plants in a high-grade highway

Root length and root length density of Lespedeza bicolor,Amorpha fruticosa,and Sea buckthorn were investigated in a country highway-TongSan highway（Tongjiang to Sanya） in Heilongjiang Province,China.The root lengths were divided into five root orders according to Pregizter sequence classification method.Results show that sea buckthorn roots are dominated by coarse roots in the horizontal growth,while L.bicolor has a large proportion of fine roots in vertical conical growth and A.fruticosa is in depth growth.Root length density of L.bicolor in all the root sequences is higher than that of sea buckthorn and A.fruticosa.On the basis of the root structure,it is inferred that L.bicolor roots mainly absorb the surface soil moisture for its normal growth;in contrast,A.fruticosa has good uptake ability to deep soil water.The root structure of sea buckthorn implies that it has a strong drought resistance.

Study on Mechanism and Control Effect of Highway Slope Ecological Protection

At present,with the rapid development of social economy,people's awareness of environmental protection continues to increase,and environmental construction and environmental protection work are put on the agenda.Highway slope greening protection is an important means to achieve social sustainable development.Developed countries carried out research earlier in this area,and China's research in this area started later.In engineering construction,ecological protection is to realize slope reinforcement and slope protection depending on the water storage and soil fixation effects of vegetation.Its slope protection can be summarized as the mechanical effect of root system and the hydrological effect of vegetation.As a basic form of slope greening protection,it is necessary for us to understand the mechanism of ecological protection and to enhance the design of ecological protection accordingly.Based on this,the article analyzed the development of slope greening protection technology and ecological protection mechanism from different angles,so as to establish a theoretical framework for future research.

Large-scale model testing of high-pressure grouting reinforcement for bedding slope with rapid-setting polyurethane

Bedding slope is a typical heterogeneous slope consisting of different soil/rock layers and is likely to slide along the weakest interface.Conventional slope protection methods for bedding slopes,such as retaining walls,stabilizing piles,and anchors,are time-consuming and labor-and energy-intensive.This study proposes an innovative polymer grout method to improve the bearing capacity and reduce the displacement of bedding slopes.A series of large-scale model tests were carried out to verify the effectiveness of polymer grout in protecting bedding slopes.Specifically,load-displacement relationships and failure patterns were analyzed for different testing slopes with various dosages of polymer.Results show the great potential of polymer grout in improving bearing capacity,reducing settlement,and protecting slopes from being crushed under shearing.The polymer-treated slopes remained structurally intact,while the untreated slope exhibited considerable damage when subjected to loads surpassing the bearing capacity.It is also found that polymer-cemented soils concentrate around the injection pipe,forming a fan-shaped sheet-like structure.This study proves the improvement of polymer grouting for bedding slope treatment and will contribute to the development of a fast method to protect bedding slopes from landslides.

Study on the Bioengineering Protection Technique for Rock Slopes in Railway

Ecological protection technique of rock slope is a new slope protection technique,and it is used widely in some supporting engineering of rock slope at railway and highway.But it is always an important research in the field of geotechnical engineering, because the study is related to many subjects and is not systemic and idiographic enough.The paper takes the rock slope of Luozhan(from Luoyang to Zhanjiang)

Thermal features of Qinghai-Tibet Railway Embankment with Crushed-stone Slope Protection in Permafrost Regions

The Embankment with Crushed-Stone Slope Protection(ECSSP) in permafrost regions is an effective measure to cool subgrade and protect permafrost.It can mitigate the engineering hazards of the Qinghai-Tibet railway in the permafrost regions. Considering the influence of the noctumal cold air during summer months in Qinghai-Tibet Plateau。

Stability evaluation and protection of slope for Laosongling-Yanji Highway

The authors analyzed the engineering geological characteristics of the slope of the study area (K75+840-K76+340). Two typical cross-sections have been chosen to analyze the failure modes after the excavation of the highway. Different types of the failure modes have been calculated and analyzed. The results show that some dealing methods have been advised to ensure the stability of the slopes.

The Application of Three-Dimensional Integrated Protection Technology in High Slope Control of Mountainous Highway

In the process of China's national economy construction,the role of highway traffic is unquestionable.And with the continuous development of society and the continuous improvement of highway grade,the work of the highway slope governance become a top priority,especially for some mountainous area highway,strengthen management of slope is very critical.The emergence of three-dimensional comprehensive protection technology has created great convenience for the management of the slope of the mountainous highway,and the safety of the mountain highway has been improved effectively.In view of this,the paper focuses on the application of three-dimensional integrated protection technology in the treatment of highway high slope in mountainous areas for reference and reference.

Ecological Protection Design Strategy for Mountain Tourism Highway Slopes

Slope ecological protection technology is a form of slope protection with high ornamental and good economic value.At present,it is widely used in highways and urban streets’slope protection works.However,its use is not very common in mountain tourism highways;hence,it is necessary to implement strategies for mountain tourism highway slope ecological protection design to promote excellent development.

Summary of Slope Ecological Protection Technology

It is an important issue for sustainable economic development to give consideration to both project development and environmental protection.At present,we must confront and seriously deal with the problems of rational utilization of resources,protection of the environment and beautification of the environment in engineering construction.This paper describes a variety of slope plant protection technology,which can not only play a good role in slope protection,but also improve the engineering environment and reflect the beauty of natural environment,so as to provide reference for slope ecological protection.

A Testing Method for Ratio Restraint Characteristics of Differential Relay Protection of Transformers

In this paper, a method to calculate the slope of the ratio restraint characteristic of a transformer differential relay protection is proposed. The method allows using some concise but effective means to get the slope. Modulating the argument of current output from ONLLY testing equipment can make the relay protection device operate, thus, the data used for calculation would be obtained naturally after several trails. In order to make sure how effective that method could be, some experiment data is given as well.

基于地质调查的缓坡地建设适宜性评价——以福建省南平市建阳中心城区为例

为构建缓坡地建设适宜性评价体系,合理划定缓坡地开发适宜区、一般适宜区及禁止建设区,科学开发利用低丘缓坡地资源,以福建省南平市建阳中心城区为研究区,在该区综合地质调查的基础上,以小流域为基本评价单元,以剥蚀阶地代替坡度和起伏度等指标,开展具有城镇建设功能指向的土地资源评价研究。以坡度、土体厚度、坡向-地层产状一致性,以及岩性建造、植被类型等为主要指标,进行地质灾害风险性评价,通过构建生态保护重要性、建设适宜性等多维评价体系,最终集成评价了缓坡地建设的适宜性。结果表明:研究区适宜城镇建设开发的缓坡地资源丰富,主要分布在严墩、新岭、兴田、将口、南林、赤岸、芹口等小流域的一级剥蚀阶地内,发生地质灾害的风险性较小,可以按照组团开发的方式逐步进行开发及利用,研究区属于地质灾害非易发区,但是西岸、水尾等小流域的二级剥蚀阶地、三级剥蚀阶地,土体较厚,坡度较陡,植被主要为杉木和毛竹,如果开发边界规划不合理,容易引发滑坡、崩塌等地质灾害。研究成果对我国低丘缓坡地合理开发利用具有较好的借鉴意义。

农田排水沟除草护坡及生态净化研究综述

对农田排水沟除草护坡及生态净化等方面的研究进行了综述,并对目前主要使用的除草技术,生态护坡技术,以及发展前沿的生态净化技术等方面的国内外相关成果进行总结归纳。然而这些方法都存在技术单一、影响环境等缺点,在对各影响因素的协同作用进行综合系统分析的基础上,提出新的解决思路。对沟道运行面临的问题与需解决的科学问题进行了探讨,旨在为现代农业灌溉排水区域建设提供参考。

高速公路边坡生态防护技术及发展趋势分析

该文详细阐述生态防护在高速公路工程建设中的重要性,主要通过植被的蓄水、保肥和固土功能来加固和保护边坡。这种防护作用主要体现在根系的力学效应和植被的水文效应2个方面。同时,深入探讨公路路基边坡生态防护技术及其机理,并试图将这些知识应用于提升生态防护技术手段。为实现此目标,结合多年野外工作实践经验,以公路边坡植物防护技术为研究对象,从多角度对边坡植树种草防护技术的发展和生态防护机理进行深入分析。

三维土工网边坡防护水土保持能力研究

路基边坡防护工程可减轻降雨对坡面土体的侵蚀作用,为深入研究坡面防护材料水土保持能力的定量表征方法,通过室内人工降雨边坡侵蚀模型试验,分析不同降雨强度和不同三维土工网防护下路基边坡的降雨侵蚀规律,提出三维土工网水土保持能力的试验测定方法及相关系数计算公式。研究结果表明:三维土工网防护边坡泥沙流失干质量明显小于相同条件下不设防边坡泥沙流失干质量,土工网防护在减少边坡侵蚀量的同时,有利于边坡侵蚀进程的快速稳定,但土工网的水土保持能力随雨强增大急剧下降。泥沙流失速度随着降雨的持续而逐渐减小,后期趋于收敛稳定,侵蚀历程采用指数函数拟合具有较好的相关性。建议设防边坡的试验降雨时间不少于70 min,不设防的边坡试验降雨时间不小于100 min。水土保持能力系数随雨强的增大呈对数函数关系减小,雨强超过100 mm/h时水土保持能力系数实测值与对数函数拟合值差异较大,建议在测定材料水土保持能力系数时雨强取20~100 mm/h,可取50 mm/h作为标准试验雨强。泡面类三维土工网水土保持能力显著优于普通三维土工网,而双泡面的三维土工网优于单泡面三维土工网。试验条件下凹凸泡面三维土工网的水土保持能力系数主要分布在1.71~3.03,建议50 mm/h雨强三维土工网水土保持能力系数不应小于1.5。

紫穗槐根土复合体特征对黄土边坡稳定性的影响

[目的]研究含水率、含根量及根系布置方式对根土复合体抗剪强度影响,揭示紫穗槐根系对黄土边坡加固机理,为黄土边坡生态防护及提高坡面稳定性工程实践提供科学参考。[方法]利用ZJ型应变控制式直剪仪进行紫穗槐根土复合体剪切试验,以无根系土为对照,分析不同含水率、含根量和布根方式对抗剪强度影响;应用FLAC 3D软件模拟紫穗槐根系分布方式对黄土边坡稳定性影响。[结果](1)随着含水率增加,抗剪强度指标黏聚力和内摩擦角均降低。(2)随着含根量增加,抗剪强度在不同含水率条件下表现出不同规律。当含水率为9.31%时,抗剪强度随着根面积比(RAR)增加呈先增加后减小的趋势,在RAR为0.15%时,抗剪强度达到最大值;当含水率为15.65%和17.44%时,抗剪强度随着RAR增加而增加。(3)“卄”形布根方式能显著提高根土复合体抗剪强度,当含水率为17.44%时,卄形布根与无根土相比,平均抗剪强度增加31.81 kPa。(4)数值模拟结果表明,根系长度、主根与铅垂方向的夹角均与稳定性呈正相关关系。[结论]通过室内试验和数值模拟研究表明,紫穗槐能较好提高黄土边坡稳定性,紫穗槐交错种植,防护效果更佳。

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。

土石坝护坡冻胀破坏水-热-力耦合数值模拟研究

针对寒区土石坝护坡普遍存在的冻胀破坏问题,选取寒区某土石坝工程为研究对象,结合土石坝工程特点,建立考虑水-热-力耦合作用的有限元计算模型。研究护坡在库水位和坝体填土水分迁移作用下冻胀破坏全过程,分析土石坝温度场、水分场和位移场的变化规律,并将位移场有限元计算结果与实测冻胀变形资料进行对比,验证有限元计算结果。研究结果表明:冻胀作用对坝坡影响深度约为2 m,坝坡浅层0~2 m范围的温度变化受外界气温影响较大,坝体内部温度相对坝坡浅层变幅小,且有一定的滞后性;负温使坝坡浅层孔隙水相变成冰,宏观上表现为未冻水体积分数的降低,坝坡浅层土石混合体孔隙水相变、坝体填土内水分向坝坡迁移和冻结峰面向坝体内部移动是护坡冻胀破坏的主要因素;大坝坝坡计算冻胀量为20~30 cm,最大值为36 cm,计算结果与实测冻胀变形资料吻合;护坡冻胀破坏主要由砂砾料垫层、坝体填土等土石混合体冻胀及冰推力共同作用引起。研究结果可为寒区土石坝护坡设计提供参考。

裸漏基岩边坡护坡设计与应用

公路工程建设过程中,裸露基岩边坡如不及时采取防护措施极易造成水土流失、滑坡等灾害的发生。结合某三级公路,工程区总体属中低山剥蚀地貌,工程沿线大部分地段基岩裸漏。裸露基岩边坡防护工程的设计与施工,对施工现场高边坡防护、防排水措施等要点进行了论述,通过边坡生态护坡设计,达到施工质量安全双优目标。