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1.
垃圾填埋场抽水试验及降水方案设计 总被引：2，自引：0，他引：2
垃圾填埋场中的渗滤液水位过高会引发一系列环境和稳定问题,工程上可用竖井抽水降低渗滤液水位。通过在填埋场现场进行抽水试验,确定垃圾土的渗透系数和抽水影响半径,在此基础上对填埋场降水的瞬态流问题进行有限元模拟,分析了抽水井口径和间距对填埋场降水的影响,提出了降水方案的设计步骤和方法。抽水试验表明,现场垃圾的渗透系数约为3.6×10-4cm/s,抽水影响半径约为20m。数值分析表明,井径的变化对于降水效果影响不大,而合理选择抽水井间距对降水十分关键。进行抽水方案设计时,应首先根据工期和降水幅度要求计算井间距,按井的出水速度选择水泵,再根据水泵确定井径,最后根据井径和过滤层形式确定钻孔尺寸并选择钻机。 相似文献
2.
城市生活垃圾填埋场地基沉降和垃圾堆体沉降受到的影响因素多,现行规范的计算方法直接采用与实际相差较大,为减少不均匀沉降对垃圾防渗层的影响、准确确定垃圾储量和保证垃圾堆体的稳定,开展垃圾填埋场沉降研究具有重要意义。垃圾填埋场沉降变形包括地基沉降和垃圾堆体沉降,垃圾堆体沉降又分为主沉降和次沉降,主沉降完成时间短于次沉降。通过对陕西省宝鸡市垃圾填埋场地基土进行沉降计算,最大沉降差超过100 mm,对垃圾防渗层不利影响较大;而对垃圾堆体沉降计算,修正后的计算值与沉降观测值非常接近。考虑不同地区地层差异和垃圾成分差异,积累沉降观测资料具有重要意义。 相似文献
3.
基于正交试验和复合单元法的排水孔优化设计 总被引：1，自引：0，他引：1
排水孔是常用的工程渗控措施,其排水降压效果将直接影响工程的安全与稳定,因此,正确模拟排水孔进而优化设计尤为重要。由于影响排水效果的因素众多,优化设计需要针对多种排水孔方案进行渗流分析,计算量较大,采用正交设计法确定排水孔方案可以大大减少渗流分析次数;传统的数值模拟方法在排水孔方案改变时需要重新绘制计算网格,前处理难以实现,采用复合单元法,无需绘制排水孔网格,因而不同排水方案的渗流分析可共用一套网格,降低了前处理的工作量和难度。基于正交试验和复合单元法的排水孔优化设计的具体步骤为：确定试验指标、因素和水平;选择合适的正交表,确定渗流计算方案;对各方案依次采用复合单元法进行渗流分析;根据渗流计算结果进行极差分析和方案优选。该方法能够迅速有效地确定出“最优”的排水孔方案,具有一定的工程实用价值,实例分析表明了该方法的可行性和优越性。 相似文献
4.
垃圾土一维压缩修正公式及有机物降解验证试验研究 总被引：2，自引：1，他引：1
针对垃圾填埋场沉降计算问题,考虑垃圾土中有机物降解及对降解过程中重度变化,在张振营压缩量计算方法的基础上推导了垃圾土一维压缩计算的修正公式;通过垃圾土有机物降解试验和计算分析,研究了有机物的降解规律;以相同配比的垃圾土进行了垃圾土柱的沉降和计算参数试验,对推导的垃圾土一维压缩计算修正公式进行了验证。研究表明,修正的计算公式能考虑更多的影响因素,有机物的降解规律可以用Richards生物生长规律来模拟,修正的计算公式能够合理地计算出垃圾土沉降的过程。 相似文献
5.
正确分析评价垃圾填埋场的地质特征和防渗方案,对垃圾填埋场的选址、设计以及施工运营极为重要。从自然环境、地层结构及岩性特征等方面阐述了淮安市某垃圾填埋场的地质特征,分析了填埋区含水层分布、厚度、赋水性等水文地质条件;结合室内试验和野外试验,综合确定了填埋区岩土层渗透系数大于1×10^-7cm／s,表明填埋区不具备天然防渗的条件,需采用人工防渗系统才能有效的阻滞垃圾渗滤液对周边环境的影响。 相似文献
6.
本文根据Terzaghi地基承载力理论,针对基坑隆起破坏时土体向基坑一侧滑移失稳的实际情况和地下水渗流对基坑稳定性影响,对Terzaghi法确定基坑抗隆起安全系数做了相应的改进,推导出新的计算抗隆起稳定安全系数方法。对影响基坑抗隆起稳定问题的因素进行了参数分析,并通过工程实例计算分析,证明新的计算方法提高了基坑抗隆起稳定设计的可靠性。 相似文献
7.
城镇垃圾填埋场场址选择受经济、交通、气候、自然地理、环境保护、水文工程地质等诸多因素影响,是一项十分复杂的工程。结合环巢湖地区的实际情况,筛选各影响因子,最终确定符合该地区的评价体系。利用分级加权法进行垃圾填埋场选址评价,将研究区依次划分为适宜区、较适宜区、适宜性差区。根据已有规范对填埋场分区结果的验证,评估方法可行,评价结果合理,为安徽环巢湖地区垃圾填埋场选址提供了可靠的地学依据。 相似文献
8.
垃圾填埋场沿底坡和背坡衬里界面发生平移破坏的工程实例较多,也有破坏面沿垃圾体内部和底坡的组合破坏形式,相应的计算分析方法有待完善。对组合破坏,根据垃圾体内部破坏面为库仑主动破坏面和组合破坏面上各点安全系数相同的假设,由刚体极限平衡条件,建立组合破坏的稳定计算方法。运用双楔体和组合破坏稳定分析方法对算例和Kettleman Hills填埋场工程实例进行计算分析。结果表明：双楔体法计算得到的最危险平移滑动破坏安全系数大于组合破坏最小安全系数;最危险破坏面是组合破坏面;对Kettleman Hills填埋场,组合滑动面也是可能的滑动破坏面。由此可见,组合破坏是垃圾填埋场可能的破坏形式之一,在进行垃圾填埋体滑动稳定分析计算时应进行组合破坏形式的计算分析。 相似文献
9.
岩质边坡的关键块体稳定性影响因素的敏感性研究 总被引：5，自引：0，他引：5
岩质边坡的关键块体是边坡安全分析和支护设计的重要方面,影响关键块体稳定性的因素较多,本文结合正交试验设计方法,对影响关键块体稳定的重要因素进行敏感性分析,评价不同物理力学参数对关键块体的安全系数的影响程度,为工程提供合理的意见。 相似文献
10.
四川省地震灾区江油市某滑坡稳定性分析与治理措施 总被引：1，自引：0，他引：1
滑坡位于四川省江油市二郎庙镇渭河村,为一牵引式土质滑坡。从分析了滑坡的结构、变形特征和影响因素入手;根据岩土样试验结果,结合地区经验和反演计算,确定滑坡稳定性计算参数;采用极限平衡法对三种工况下滑坡体进行稳定性和剩余下滑力计算。计算结果表明在天然状态下滑坡处于稳定状态,在连续降雨、暴雨及地震影响下,整体处于稳定～基本稳定状态,存在小规模滑移垮塌以及整体滑移的可能性。结合工程实际对滑坡进行治理设计,提出裂缝夯填＋地表截排水＋抗滑桩治理措施。 相似文献
11.
A bioreactor landfill is operated to enhance refuse decomposition, gas production, and waste stabilization. Some of the potential
advantages of bioreactor include rapid stabilization of waste, increased landfill gas generation, gain in landfill space,
enhanced leachate treatment, and reduced post closure maintenance period. Due to the accelerated decomposition and settlement
of solid waste, bioreactor landfills are gaining popularity as an alternative to the conventional Subtitle D landfills. However,
the addition of leachate to accelerate the decomposition changes the physical and engineering characteristic of waste and
therefore affects the geotechnical characteristics of waste mass. The changes in the physical and mechanical characteristics
of solid waste with time and decomposition are expected to affect the shear strength of waste mass. The objective of this
paper is to analyze the stability of solid waste slopes within the bioreactor landfills, as a function of time and decomposition.
The finite element program PLAXIS is used for numerical modeling of bioreactor landfills. Stability analysis of bioreactor
landfills was also performed using limit equilibrium program STABL. Finally the results from finite element program PLAXIS
and limit equilibrium program STABL are compared. GSTABL predicted a factor of safety of more than 1 in all the cases analyzed,
whereas PLAXIS predicted a factor of safety of less than 1 at advanced stages for a slope of 2:1. However, the interface failures
between solid waste and landfill liners have not been considered in this paper. 相似文献
12.
Estimation of seismic yield acceleration for the municipal solid waste landfills is the basic step for design to mitigate
the hazard of earthquake on landfills. For most of the landfills constructed in the seismic zones, influence of the vertical
component of seismic acceleration is often neglected assuming that it is not in phase with the horizontal seismic acceleration
and hence does not affect the design parameters largely. Conventional pseudo-static analysis using limit equilibrium method
does not consider the variation of seismic inertial forces with time and also effect of vertically propagating shear and primary
waves, which can have serious effect on the design values. To overcome the limitations of existing methodology, in the present
study, pseudo-dynamic approach, which takes into account the effects of time, primary and secondary waves, frequency of excitation,
is applied for the first time for dynamic analysis of landfills for three different typical practical geometries of landfills.
Chosen sets of landfills resemble some of the existing landfill geometries. Design equations and charts are developed for
factor of safety against base sliding and seismic yield acceleration for these three typical landfill geometries. The results
are compared with the similar results obtained by using conventional pseudo-static analysis, and the influence of vertical
seismic acceleration on factor of safety against base sliding and yield acceleration is reported. 相似文献
13.
Annual variation in the amount and composition of waste deposited in the Gimpo #2 landfill, the largest landfill around Seoul, Korea, is reviewed, and the stability of the same landfill is analyzed during waste disposal. For the stability analysis, three empirical stability prediction methods, i.e., linear stability, displacement velocity, and curve stability methods, are used to analyze field-measured settlement and horizontal displacement data. The analysis indicated that national waste management policy has greatly influenced the annual variation in the amount and composition of waste deposited in the landfill. Continuous measurement of geotechnical data and the use of stability analysis based on these data are necessary for landfills on seashore clay foundation. Stability of the landfill must be examined with various methods to ensure accurate determination of its stability. 相似文献
14.
The aim of this work is the joint application and integration of non-invasive geoelectrical methods for studying the landfill of Savoia di Lucania (Southern Italy). This landfill for its engineering features and small dimensions (70 m × 30 m × 6 m) represents an optimal test site to assess a geophysical survey protocol for municipal solid waste landfills investigation and monitoring. The landfill of Savoia di Lucania has been built with a reinforced concrete material and coated with a high-density polyethylene (HDPE) liner. Three electrical resistivity tomographies (ERT), two self-potential (SP) map surveys and one induced polarization (IP) section have been performed, both in the surrounding area and inside the waste landfill. The geophysical investigations have well defined some buried boundaries of the landfill basin and localized the leachate accumulation zones inside the dumpsite. Comparison of our results with other engineering and geological investigations could be the key for evaluating the integrity of the HDPE liner. Finally, the joint use of the ERT, IP and SP methods seems to be a promising tool for studying and designing new monitoring systems able to perform a time-lapse analysis of waste landfill geometry and integrity. 相似文献
15.
为了人类社会的可持续发展,对产量惊人的生活垃圾进行合理地处置成为世界各国亟待解决的问题之。垃圾填埋法是符合处置经济性和技术可行性的理想方案。垃圾填埋场投八运营后,如何防止被填埋垃圾及其次生有害物质进八周围环境,是垃圾填埋场设计环节必须考虑的关键问题之。在城市垃圾填埋场底部衬里系统及封盖系统中设置水力屏障,能有效防止填埋场中所产生的废液、废气向周围环境中迁移。水力屏障通常由土工合成材料与膨润土防水垫或压实粘土组成,形成个多界面的复合衬里或复合封盖体系。这种多界面力学特性以及潜在薄弱面对垃圾填埋场的稳定性具有控制作用,因此成为业界的研究重点。本文依据填埋场封盖和衬里土工合成材料多界面力学特性的最新研究,对所取得的研究成果进行分析和讨论。 相似文献
16.
针对填埋场衬垫系统薄弱界面容易失稳,在加肋土工膜与砂土界面力学机制分析的基础上,改进了传统双楔体分析法,考虑了加肋土工膜肋块端部端承阻力对衬垫系统稳定性的影响,建立了加肋土工膜衬垫系统稳定性分析解析解。结合某实际工程初步设计,对加肋土工膜衬垫系统进行了稳定性分析,探讨了肋块形状、肋块高度和加肋间距对衬垫系统安全系数的影响。分析结果表明,该解析解能更好地计算加肋土工膜衬垫系统的安全系数。当加肋间距为20 mm时,肋块高度对安全系数的影响较大;当肋块高度一定时,安全系数随着加肋间距增加而逐渐减小;在加肋间距大于200 mm之后,加肋土工膜已接近光面土工膜的剪切特性。 相似文献
17.
不同降雨模式下山谷型垃圾填埋场水分运移及其稳定性研究 总被引：2，自引：0，他引：2
近10年的运营经验表明,国内南方地区第1批建造的山谷型垃圾填埋场中的渗滤液水位一般较高。同时,现有研究表明,降雨入渗引起渗滤液水位过高是垃圾填埋场失稳的主要诱因之一。因此,研究强降雨条件下山谷型垃圾填埋场的水分运移规律及其稳定性,具有重要的现实意义。基于七子山填埋场浅层、中层和深层垃圾土的土-水特征曲线和Brooks-Corey公式,利用非线性拟合技术得到垃圾土的渗透性函数;运用饱和-非饱和渗流理论,对递减型、中心型、增强型和平均型4种降雨模式下七子山填埋场的水分运移进行了数值计算;利用极限平衡理论,对不同降雨模式下七子山填埋场的稳定性进行了分析。结果表明,降雨模式对山谷型垃圾填埋场内的水分运移规律和填埋场的稳定性有显著的影响,递减型降雨模式下填埋场内孔隙水压的变化最大,同时填埋场稳定系数也下降最为明显,为最不利降雨模式;经历7 d 746 mm的极端强降雨后,七子山填埋场具有极大的失稳隐患。 相似文献
18.
Translational failure analysis of landfill with retaining wall along the underlying liner system 总被引：3，自引：3，他引：0
The scope of this paper is to develop a new three-part wedge analysis method, introducing the effects of solid waste shear
strength and retaining wall on the translational failure of landfills. A typical landfill can be divided into three parts:
an active wedge lying on the back slope that tends to cause failure, a passive wedge, and a retaining wall resting on the
foundation or liner system that helps to resist any movements. Using this method, the amount and direction of the interwedge
force can be calculated, and the upper and lower bound solutions for the landfill stability, i.e., FS
max and FS
min, can be easily determined. When an average factor of safety, FS
ave, is used as a solution replacing the true factor of safety, FS
true, the upper bound of difference between FS
ave and FS
true is not more than 5% for all considered cases in this study. The retaining wall of the landfill seriously affects the value
of the factor of safety; simply ignoring the retaining wall will lead to serious underestimation of the factor of safety.
The factor of safety at the interface between active and passive wedges is defined as FS
V. The values of FS
V/FS
ave vary between 1.95 and 2.05 and are concentrated around 2.0. The approximate solutions of FS with adequate accuracy can be obtained by assuming FS
V = 2FS. 相似文献
19.
固体废弃物填埋场长期使用过程中,垃圾土的强度参数随着龄期的变化而变化。在进行固体废弃物填埋场边坡稳定分析时考虑按龄期分层,基于极限分析上限理论,提出了转动-平动组合和多块体平动两种破坏机构。通过水平分层土坡算例的对比分析,验证两种破坏机构的合理性和有效性。进而对填埋场算例按龄期分层分析,结果表明,极限分析上限解的安全系数和破坏机制与强度折减有限单元法非常接近,多块体平动机构通过随机搜索所得的最危险滑裂面优于转动-平动组合机构。最后分析西班牙Coll Cardús固废填埋场,此填埋场是按龄期分层的典型复杂填埋场,运用两种破坏机构所得的安全系数和最危险滑裂面与有限单元法相符。算例分析表明,在不考虑水位的情况下,填埋体堆填时间越长越有利于填埋场的稳定。当填埋体按低、中、高龄期分层形成时,填埋场的整体稳定安全系数介于中龄期和高龄期的均质边坡之间。 相似文献