岩土工程中地下水位变化对土质稳定性的影响探究

在岩土工程中,地下水位的变化对土质稳定性有巨大影响。首先基于岩土工程和地下水位的基本概念,探讨地下水位与土体稳定性的基本关系。其次,通过详细研究地下水位变化对岩土强度、岩土压缩性以及土体孔隙分布和土体构造的影响,深入理解地下水位变化和岩土工程特性的关系。利用定量分析,阐述了地下水位变化对土质稳定性的影响以及影响机理,并提出了地下水位变化下岩土工程稳定性的控制策略。

土质稳定性对生态护坡工程建设的影响分析

生态护坡是岩土工程与环境工程相结合的产物,是生态水利工程中至关重要的组成部分。对生态护坡的类型进行了介绍,指出水利工程中生态护坡建设与土质稳定性存在的问题,分析两者之间的关系,重点分析强降雨条件下二者的稳定性关系,同时针对存在问题提出相应的解决方法,对边坡工程的预防和防治具有一定的参考价值。在开展水利工程时,应根据工程土质稳定性特点选取合适的生态护坡技术,以保证生态护坡工程建设的耐久性。

河道生态护坡治理工程受土质稳定性影响探析

河道护坡是为保证边坡稳定性而采取种植与铺砌的各类措施,其中生态护坡是生态水利工程中将环境与岩土相结合的重要组成内容。文章通过分析生态护坡常见的各种类型,探讨了土质稳定性与生态护坡建设过程中存在的主要问题,并进一步揭示了二者之间的相互关系,在此基础上深入探析了强降雨条件下土质稳定性对生态护坡建设的影响作用,提出了相应的解决方法。研究表明:为保证生态护坡治理工程的适用性与耐久性,应在水利工程建设实施前结合土质稳定性特点,选择科学、合理的生态护坡技术;研究成果可为河道生态治理和预防提供一定决策依据。

降雨型土质边坡稳定性三因素图谱评价方法研究

降雨是边坡工程易发环境中一个重要的触发因素。以安溪县某边坡为例,采用有限元法和强度折减法相结合的方法,综合分析降雨强度、持续时间和边坡稳定性安全系数三因素之间的关系,建立三者之间的三维关系数据图谱。通过三维数据图谱,直观表达了降雨强度、持续时间和安全因素之间的复杂关系,为边坡稳定性分析提供了新的视角和理解。结果表明:降雨强度和持续时间,对边坡安全系数和边坡变形有显著影响。建立降雨强度和持续时间的多因子三维图谱,由安全系数划分出边坡在不同降雨工况下的评价等级,更直观地表达了数据之间的变化趋势和交互特征。

土质及软岩边坡地震稳定性影响因素分析

汶川地震后,拉剪破裂面已经成为岩土工程界公认的边坡破坏面,传统的剪切破坏面不符合动力边坡破坏的实际情况,文章修正了传统动力时程分析法,提出一种全新的动力边坡稳定性判断方法。此种方法在理论和实际中都有很大优势,为了保证此种方法计算结果的唯一性和准确性,则必须保证判断动力边坡的判据不受其他因素的影响。为此文章通过采用FLAC软件模拟土质及软岩边坡,计算分析弹性模量、时间间隔和局部阻尼系数的选取对土质及软岩边坡动力稳定性安全系数的影响,以此来验证此种动力边坡稳定性判断方法是否可行。

Aggregate Stability and Its Relationship with Some Chemical Properties of Red Soils in Subtropical China

The stability of aggregates in the surface soil is crucial to soil erosion and runoff generation. Thus, to understand the stability and the breakdown mechanisms of soil aggregates as well as the relationship between aggregate stability and selected soil chemical properties, such as different forms of Fe and Al oxides, organic matter, CEC and clay content, the aggregates of slightly and severely eroded red soils derived from Quaternary red clay in subtropical China were analyzed using the routine wet sieving…

Light Fraction Carbon and Water-Stable Aggregates in Black Soils

The distribution of light fraction carbon （LF-C） in the various size classes of aggregates and its relationship to water- stable aggregates as well as the influence of cultivation on the organic components in virgin and cultivated black soils were studied by wet sieving and density separation methods. The total organic carbon （TOC） and LF-C were significantly higher （P≤ 0.05） in the virgin soils than in the cultivated soils. The LF-C in aggregates of different size classes varied from 0.9 to 2.5 g kg^-1 in the cultivated soils and from 2.5 to 7.1 g kg^-1 in the virgin soils, whereas the ratio of LF-C to TOC varied from 1.9% to 7.3% and from 5.0% to 12.2%, respectively. After being incubated under constant temperature and controlled humidity for three months, the contribution of LF-C to TOC sharply decreased to an amount （1.7%4.5%） close to the level in soils that had been cultivated for 20 to 25 years （1.3%-8.8%）. As a result, the larger water-stable macro-aggregates （especially 〉 1 mm） decreased sharply, indicating that the LF-C pool in virgin soils declined quickly after cultivation, which reduced the water stability of soil aggregates.

Effect of Cultivation on Soil Organic Matter and Aggregate Stability

Agricultural sustainability relates directly to maintaining or enhancing soil quality. Soil quality studies in Canada during the 1980 s showed that loss of soil organic matter (SOM) and soil aggregate stability was standard features of non-sustainable land management in agroecosystems. In this study total soil organic carbon (SOC), particulate organic matter (POM), POM-C as a percentage of total SOC, and aggregate stability were determined for three cultivated fields and three adjacent grassland fields to a…

The stability analysis of expansive slope in Jing-Yi Expressway

This paper firstly introduces the distribution of weathered layers, and then presents the relationship between watercontent and expansive force and the working model of expansive forces in expansive soil slopes. Taking the expansive soil slope ofJing-Yi Expressway as example and applying the Slices Method, this paper puts forward the stability calculation method con-sidering the effect of expansive forces, and also proposes the treatments.

梧州市花岗岩残积土的工程特性

花岗岩残积土其工程特性兼具砂土与粘性土的性质,是一种力学性质较好的混合土,其压缩性指标难以采用室内试验确定,应以原位测试为依据;抗剪特性同时具有砂土与粘性土的性质,但土质边坡的稳定性主要取决于土中原生与次生结构面的空间组合。

New methods of safety evaluation for rock/soil mass surrounding tunnel under earthquake

The objective of this work is to obtain the seismic safety coefficient and fracture surface and proceed with the seismic safety evaluation for the rock mass or soil mass surrounding a tunnel,and the limitation of evaluating seismic stability is considered using the pseudo-static strength reduction.By using the finite element software ANSYS and the strength reduction method,new methods of seismic safety evaluation for the rock mass or soil mass surrounding a tunnel are put forward,such as the dynamic finite element static shear strength reduction method and dynamic finite element shear strength reduction method.In order to prove the feasibility of the proposed methods,the results of numerical examples are compared with that of the pseudo-static strength reduction method.The results show that 1) the two methods are both feasible,and the plastic zone first appears near the bottom corners; 2) the safety factor of new method Ⅱ is smaller than that of new method I but generally,and the difference is very small.Therefore,in order to ensure the safety of the structure,two new methods are proposed to evaluate the seismic stability of the rock mass or soil mass surrounding a tunnel.A theoretical basis is provided for the seismic stability of the rock mass or soil mass and the lining surrounding a tunnel and also provided for the engineering application.

Short-term deformation behavior model of endangered earthen heritage slope after conservation in Jiaohe Ruins

Cliff deformation behavior after conservation is of great significance for evaluating the conservation effect and discovering the dynamical law of soil. Modeling on deformation behavior is beneficial to the quantitative evaluation of interactions between soil mass and structures as well as the forecast. Based on cliff conservation engineering of Jiaohe Ruins （the largest raw soil heritage site in the world）, data of horizontal deformation of the upper cliff were obtained by using Nanrui-made NDW-50 displacement device （precision： 0.01 mm, frequency： 15 min^-l）. Regression analysis indicates that deformation behavior models include exponential growth, linear growth and parabolic growth types, while daily deformation presents more intense periodicity （24 h）. The deformation is less than 1.5 mm during monitoring period, which has no impact on the stability of cliff. Deformation behavior provides the mutual duress and interaction between soil and engineering intervention. In addition, deformation mode attaches tensely to the damage pattern of the cliff. The conclusions are of importance to the stability evaluation of the carrier along Silk Road.

Aggregate Development and Organic Matter Storage in Mediterranean Mountain Soils

Soil aggregation and organic matter of soils from the pre-Pyrenean range in Catalonia (NE Spain) were studied,in order to assess their quality as carbon sinks and also to select the best soil management practices to preserve their quality.Aggregate stability,organic carbon and micromorphology were investigated.The highest amount of organic carbon was found in alluvial,deep soils (228 Mg C ha -1 ),and the lowest was in a shallow,stony soil with a low plant cover (78 Mg C ha -1 ).Subsurface horizons of degraded soils under pastures were the ones with smaller and less-stable aggregates.Fresh residues of organic matter (OM) were found mostly in interaggregate spaces.Within the aggregates there were some organic remains that were beginning to decompose,and also impregnative nodules of amorphous OM.Although OM was evenly distributed among the aggregate fractions,the larger blocky peds had more specific surface,contained less decomposed OM and had a lower organic/mineral interphase than smaller crumb aggregates,which were also more stable.Soil carbon storage was affected primarily by the OM inputs in the surface horizons.In order to store organic carbon over the mid- and long-term periods,the mechanisms favouring structuration through biological activity and creating small aggregates with intrapedal stable microporosities seemed to be the most effective.