ABSTRACT Currently, the destabilization mechanisms of slopes due to rainfall infiltration are not fully understood. We conducted physical model tests to measure displacement and pore water pressure from rainfall, using the data to validate numerical models. This study explores how rainfall intensity and duration affect these measures across loess slopes with varying steepness. The goal is to understand slope responses to different rainfall conditions. Our findings indicate that steeper gradients see modest increases in displacement and pore water pressure at the top and mid‐slope, but these increases are more pronounced at the toe. The changes at the toe and mid‐slope are driven by infiltrated rainwater volume and soil compressive behavior, while top‐slope displacement is primarily due to infiltration. Continuous deformation was observed during and after the rainfall events. Post‐rain, pressure from saturated soil at the slope's apex amplifies pore water pressure at the toe, influenced by gravitational forces and retained water pressure. This underscores the complex interactions affecting slope stability in wet conditions. Understanding loess slopes' responses can improve predictive models and mitigation strategies, reducing infrastructure and safety risks in these vulnerable areas.

This study investigates the stress-strain relationship and damage evolution mechanism of alkali-activated coal gangue powder-based geopolymer solidified loess under uniaxial compression. Uniaxial compression tests were conducted on specimens with different mix proportions and curing ages, followed by the development of a damage constitutive model based on damage mechanics theory. The experimental results demonstrate that the compressive strength of the solidified loess increases with extended curing periods and higher binder content. By integrating Lemaitre's strain equivalence principle with a composite power function, a damage constitutive model was derived. The model exhibits strong consistency with experimental stress-strain curves, thereby validating its rationality and the accuracy of elastic coefficient determination. These findings provide critical insights into the damage evolution patterns during uniaxial compression failure of alkali-activated coal gangue powder-based geopolymer-modified loess. Furthermore, this study establishes a theoretical framework and offers practical references for characterizing damage constitutive relationships in geopolymer-stabilized soils.

This study explores the use of alkali-activated coal gangue powder (CGP) as a sustainable stabilizer to improve loess performance, aiming to promote industrial solid waste valorization and low-carbon geotechnical construction. The effects of binder dosage on flowability, unconfined compressive strength (UCS), and water stability were systematically evaluated, and microstructural mechanisms were examined by using X-ray diffraction (XRD) and scanning electron microscopy (SEM). Results show that increasing binder dosage reduced the flowability and setting time while maintaining values above 160 mm, ensuring practical applicability. UCS increased with curing age and binder dosage, reaching 2.06 MPa at 28 days with rapid early strength development. Water stability was significantly enhanced, as no disintegration occurred after 24 h of immersion, and high-binder samples exhibited a buoyant mass increase 4.25 times that of low-binder samples, reflecting improved soil compactness and resistance to capillary water absorption. Microstructural analysis revealed that alkaline activation of CaO, SiO2, and Al2O3 promoted calcium silicate hydrate (C-S-H) gel formation, creating a stable spatial network that strengthened particle bonding and minimized porosity. These findings indicate that alkali-activated CGP can effectively stabilize soil for engineering applications, including road subgrades, foundation improvement, and embankments, providing both sustainable material utilization and reliable geotechnical performance.

This study addresses the challenge of deformation and failure on loess slopes, predominantly triggered by rainfall, by evaluating the efficacy of various slope protective measures. Recognizing the escalating preference for ecological protection techniques, this paper focuses on identifying optimal strategies that align with local rainfall patterns. A comprehensive analysis of loess slopes under diverse rainfall conditions was conducted, encompassing scenarios with prime soil, stabilized soil, and no protection. Utilizing the finite element software ABAQUS, a sophisticated rainfall infiltration slope model was developed and validated against experimental data. The investigation reveals that under low rainfall intensities, the choice of protective material—whether stabilized or prime soil—exerts limited influence on slope pore pressure. In contrast, at higher rainfall intensities, the impact of these protective materials on slope stability becomes significantly more pronounced.

Due to the special characteristics of loess soil, once the stability of the slope is not detected in place, it is easy to cause serious loss of life and property, so this paper is based on the limit equilibrium method to analyze the stability of loess slopes under different rainfall intensities. The simplified Bishop’s method, the proposed static method, and the strength reduction method under the limit equilibrium method are studied to provide a reference basis for subsequent research. Explore the law of rainwater infiltration in loess under different rainfall conditions, construct a water-wetting model, investigate the seepage law of loess slope, and detect the degree of wetting and seepage of loess soil under different rainfall conditions. Combining the principle of effective stress of saturated soil, analyze the mechanical characteristics of the unsaturated soil on the loess slope. The stability of loess slopes under natural conditions and seismic conditions is analyzed, and the pore water pressure and shear strength of the sliding surface of loess slopes are analyzed under different rainfall conditions. The experimental data show that the slope safety coefficient of the simplified Bishop-limit equilibrium method under natural conditions is 1.118, and the difference with other algorithms is about 2.9%, which shows that the safety coefficient of the simplified Bishop-limit equilibrium method is more accurate to detect when combined with the slope stability model. When the rainfall intensity is 15, 30, 45, 60, and 75mm/h, the slope safety factor is 1.18, 1.14, 1.125, 1.12, and 0.98, respectively, the rainfall intensity is negatively correlated with the slope safety factor.

The aim of this study is to investigate the engineering properties and solidification mechanism of loess through the use of alkali-activated coal gangue powder with sodium silicate. Experimental methods and comprehensive analysis were employed to examine the effects of different proportions of alkali-activated coal gangue powder with sodium silicate on the engineering properties of loess, including mass shrinkage, compressibility, and shear strength. Additionally, scanning electron microscopy was utilized to gain in-depth insights into the interaction and solidification mechanism between loess and alkali-activated coal gangue powder. The results show that the sodium silicate alkali-activated gangue powder curing loess has significantly improved the compressive strength and shear strength of the loess. With a ratio of 7 : 2 : 1, the 28 days compressive strength of solidified loess is 1.7 MPa, and the shear strength is 67.92 kPa, which is 1.91 and 2.13 times the 28 days compressive strength and shear strength of unmixed gangue powder and sodium silicate specimens respectively. The hydration-hydrolysis reaction, ion-exchange reaction, and volcanic ash reaction of the gangue powder under an alkaline environment generated hydrides that filled the pores between soil particles, enhanced the interparticle cohesion, and made the internal structure of the specimens denser, improving the engineering performance of loess solidification. The proposed sodium silicate alkali-activated gangue powder curing loess mechanism can provide a theoretical reference for the engineering application of gangue powder and the curing modification of loess.

Loess tablelands are large-scale platforms with flat top surfaces in the center of Chinese Loess Plateau, such as Dongzhiyuan, which is a ∼900 km2 loess stratum, with the thickness larger than 200 m. The break of loess tablelands is widely reported due to the retreat of gully systems, resulting in serious social problems and economic losses. The retreating rate of large gullies has been 0.5–6.6 m/year over the past 2,000 years, estimated by the calculation of erosion modulus, literature archaeology, and field monitoring. The retreating rate of a small gully can reach 7.5–27.0 m/year after a rainstorm. To protect the farmland, buildings, roads, and pipelines near to the gully head areas, a project named Gully Stabilization and Highland Protection (GSHP) was launched by the local government, including the small watershed management (SWM) around loess slopes and gully channels and sponge city construction (SCC) achieved by improving the drainage system of tableland surfaces. These efforts improve the soil and water conservations, although they contribute less to controlling gully expansion. From the perspective of mutual promotion of gravity erosion and hydraulic erosion, this paper proposes a technical framework for GSHP, focusing on the avoidance of geological disaster. This case study reports on an illustrative GSHP project, the restoration of Huoxianggou gully, including the backfilled loess embankment across the gully for convenient urban transportation, and the stabilization of unstable loess slopes. After the implementation, the retreat of the gully head has been stopped, and the soil erosion rate has been reduced by 90%.

煤矸石的回收利用作为"十四五"期间国家大宗固体废弃物综合利用的重要关注点之一,推进煤矸石在工程建设领域的应用对于助力生态文明建设和经济社会高质量发展具有重要意义.为了合理推进煤矸石粉的利用,将煤矸石粉作为掺和料,掺入生土材料中进行生土改性研究,并设计了 4组配合比方案,制作了 0102 mmx116 mm圆柱体试件.针对不同配合比的改性试件,在自然条件下养护28 d后呈未烘和烘干2种状态下,对其进行轴心抗压强度试验,分析其试验现象、试验过程、抗压强度、荷载-位移曲线,以研究不同煤矸石粉掺量对改性生土抗压强度的影响规律.试验结果表明:单掺煤矸石粉在自然条件下养护28 d后,未烘试件抗压强度有所下降;烘干试件抗压强度略有提高.总体而言,单掺煤矸石粉进行生土改性效果不佳,建议进一步开展微观试验以揭示其改性机理,并进行与其他材料复掺的生土改性研究.

为了研究桩板墙施工振动对邻近建筑物的影响,依托于某道路连接线工程,对桩板墙施工振动的传递规律进行了现场监测,获得了距离振源不同位置处的速度时程和速度频谱,并对不同位置处3个方向振动频率和速度峰值进行了统计分析.结果表明:桩板墙施工引起的邻近建筑物振动表现为整体振动,但以水平振动为主;随着测点远离振源,振动呈衰减趋势,符合振动波传递规律.此外,还给出邻近建筑物振动实测资料的评价分析结果,可为类似工程的施工提供一定的参考和借鉴.

我国的建筑行业中,目前装配式建筑是发展中的热点问题,但从工程设计施工至工程管理等各方面的装配式建筑专业技术人才,还远不能满足市场需求.依据装配式建筑的工程施工技术特点、内容,通过探索基于装配式建筑土木工程施工课程实践教学建设的现状、教学方式等相关问题,明确指出了实践师资、教材、实践基地、VR教辅资源等实践教学活动的建设途径,以期对高校装配式建筑应用型人才的教学培养模式进行推动,促进综合化配套改革,为新时期建设提供急需的专业人才,增强毕业生的就业能力.

在遥感和GIS技术的支持下,利用2000-2016年MODIS INDV数据,结合一元线性回归法和F检验分析了陕甘宁黄土高原区植被覆盖的空间格局及其变化趋势,并从气候和人类活动2个方面探讨了影响植被覆盖变化的主要原因.结果 表明,20002016年陕甘宁黄土高原区植被覆盖度呈上升趋势,而在空间上表现为由东南向西北逐渐递减的变化规律;超过50％区域的植被有明显增加,且主要集中在陕西黄土高原区,其余大部分地区植被变化不显著;极端气温对植被生长有明显抑制作用,而相对适宜的温度(9～10℃)会促进植被生长;降水与植被INDV的相关性以300mm等降水量线为界,以北表现为负相关,以南则呈正相关.研究结果可为当地的生态环境保护、生态系统恢复和可持续发展提供理论依据.

Soil erosion is a global environmental problem, and land-use changes have significantly altered soil erosion processes. However, soil erosion processes and their major influencing factors vary among different landforms. Dongzhiyuan (DZY), that is, the largest tableland in the Loess Plateau (LP), has experienced significant land-use changes in previous decades. However, little is known about impacts of land-use changes on soil erosion across different landforms in the DZY tableland. LANDSAT images from 1987, 1997, 2007, and 2017 were used to extract information on the land-use changes in DZY. The decreases of farmland amount to 2.57 x 10(4) ha from 1987 to 1997, forest by 1.30 x 10(4) ha from 1997 to 2007, and grassland by 2.74 x 10(4) ha from 2007 to 2017. Urban areas increased by 1.41 x 10(4) ha from 1987 to 2017. The soil erosion estimated by the revised universal soil loss equation (RUSLE) and Chinese soil loss equation (CSLE) was 11.3 and 5.8 t ha(-1) yr(-1), respectively. The conversion from urban areas to farmland and grassland increased soil erosion. Changes from farmland to grassland and forest to grassland, intensified soil erosion; the severity of soil erosion depended on the intensity of the land-use changes. Urban expansion caused a smaller decrease in soil erosion in the loess tableland, whereas vegetation restoration, to a large extent, decreased soil erosion in the loess gully area. Anthropogenic activity accelerated soil erosion before 1997, but slowed its influence after 1997. This study provides a reference for land-use planning and soil water conservation in the LP.

结构力学作为土木工程专业的专业基础课程之一,对于其他专业课程的学习起到承前启后的重要作用,也是学生学习过程中晦涩难懂的一门课程.因此,首次提出以结构力学教学为中心,基于目前在全球得到快速发展的慕课教育技术平台,同时引入国外翻转课堂的教学方法,使结构力学电算、结构模型设计实践与结构力学课程学习相结合,从教学内容体系规划、教学方法等方面改革,加强对土木工程专业结构力学课程的建设,旨在提高学生学习的主体性、趣味性和参与度,形成了"知识—训练—实践"良性循环的新型结构力学课程教学模式,从而提高土木工程专业学生面向工程实际的力学分析与计算能力.

水资源短缺是黄土高原半干旱地区经济、社会以及生态可持续发展的"瓶颈",因此定量地对黄土高原半干旱地区水资源进行供需分析和合理配置研究,对城市化的快速推进和水资源可持续利用具有重要的意义.通过对典型的黄土高原半干旱地区庆阳市西峰区进行研究,以其水源地和水资源现状为研究对象,在预测近远期需水量、分析现状供水能力的基础上,以2014年为现状年,以2020和2030年为规划年,对水资源进行供需分析,得到了其在不同水平年的水量余缺结果,并且依据结果提出了水资源配置方案和水资源管理、调控的建议.

Soil erosion is a major environmental problem for human survival and sustainable development, which has been seriously threatening human ecological security. The Loess Plateau is one of the most severe areas of soil erosion in the world. Unreasonable land use is an important cause of soil erosion. In recent years, the significant progress has been made on land use and soil erosion. The paper finds: (1) soil erosion models have gradually improved; (2) assessment results of land use and soil erosion which are based on RS and GIS technology have become more accurate and efficient; (3) the research has been gradually increasing at different spatial and temporal scales. However, the current existing models are less versatile and most of them are focus on single-scale research. The achievement of the above results and the continuous research in the future are of great significance for the optimization of land use pattern and the comprehensive management of regional soil erosion in the Loess Plateau.

为了了解3℃恒定低温条件下水胶比和掺和料对胶凝材料的水化热的影响规律,根据GB/T 12959-2008《水泥水化热测定方法》中的直接法,测定了3℃恒定低温条件下不同水胶比和掺和料的胶凝材料在28d内的水化热值.试验结果表明:3℃恒定低温条件下,胶凝材料水化热值随着水灰比的增大而上升.水灰比一定时,胶凝材料水化热分别随着粉煤灰和矿粉掺量的增加而下降,但是两者之间不成正比关系.通过不同掺和料掺量与不掺掺和料的胶凝材料水化热对比分析发现,加入掺和料后初期对胶凝材料水化热的降低效果较为明显,但后期影响不大,28d时水化热差值均在10％以内.

水文地质调查是为国民经济建设、社会发展、生态环境建设保护提供基础水文地质资料和可供规划的区域地下水资源而进行的一项基础性水文地质工作.本文通过实地勘探,全面收集和整理水文地质相关资料,对庆阳市西峰区区域进行了调查研究,根据地貌成因及其形态特征,将西峰区地貌划分为黄土塬、黄土残塬梁峁沟壑和堆积侵蚀河谷三种类型,分析了区域内地层岩性、地表水系和地下水条件及其含水层特征,为庆阳市西峰区区域内水文地质研究奠定了良好的基础,并为当地水资源的进一步开发利用提供了科学依据.

通过对甘肃省镇原县城镇供水开展水文地质调查,在分析水源地含水层特征、地下水类型、补径排条件以及地下水化学特征的基础上,计算地下水资源总量,采用综合评价法及单项组分法进行水质评价.结果表明,镇原县城市供水水源地罗汉洞组承压水天然补给量为:Q天补=9851.43m3/d,弹性储存量为2.92×104m3,而其现状开采量为4495m3/d,供水水源地能够满足城市供水需要;供水区地下水未受污染,供水水源符合生活饮用水质量标准,水质属较好水.

In arid regions,such as Hexi Corridor in Gansu Province,Northwest China,wetland is rare and valuable especially.There are four wetlands in the middle reaches of the Xida River in Yongchang County of the corridor,i.e.,Liukezhuang,Jiaojiazhuang,Beihaizi and Shengrongsi,with an total area of 20.38 km2.Formation of the wetlands results from hydrogeological conditions,which are controlled by landform-structure,and intertransformation and interaction of surface water and groundwater (spring water).Since the 20th century,wetland area has been gradually reducing and shrinking in the middle reaches with climate warming and the overuse of water resources.The main counter measures to protect the limited wetland resources of this area are to reinforce the ecological environment protection in runoff formation and water conservation areas in the upper reaches of the Xida River and to reduce the use of surface water and exploitation groundwater in the middle reaches.

[Objective] The risk of desertification was evaluated in Loess Plateau to provide scientific basis for the restoration,construction and protection of ecological environment.[Methods] Data of landform,climate,vegetation,soil and other socio-economic data were collected.Spatialization and digitalization were conducted using GIS and remote sensing.Upon which,desertification reasons were analyzed,and evaluation indices and risk assessment model were framed based on index of environmentally sensitive areas.[Results](1) According to the bio-physical index in the framed model,under the scenario only considering natural factors as soil,climate and vegetation,25.2 ％ of Loess Plateau was determined as high desertification risk area,where desertification was worst;62.8％ and 11.5％ of Loess Plateau were determined as moderate and potential desertification risk areas;only 0.5％ was considered having no risk.(2) If both natural factors and human interference were considered,risk area changed:coverages of extreme low,low and extreme high risk levels decreased by 5.6 ％,1.1％ and 3.8 ％,respectively;whereas,coverages of lower and higher risk levels increased by 4.4％ and 4.5％.[Conclusion] (1) The ESAI model can well explain the spatial distribution pattern of desertification risk of Loess Plateau,and the degree of desertification is gradually weakened from the northwest to the southeast.(2) Human activities have upset the long-term evolved stability of the natural eco-system to some extent,and have narrowed the gap between different risk levels of desertification.