管内小药量水下爆炸平面冲击波形成方法及其应用

水下爆炸过程中存在冲击波、气泡、冲击波绕射等多种效应的耦合,给水下爆炸毁伤机理的研究带来了一定难度。为了对上述多种效应进行解耦,文中提出一种管内小药量水下爆炸平面冲击波形成方法,采用数值仿真和理论分析对管内水下爆炸平面冲击波的衰减规律进行了研究。研究结果表明:在管道端部放置装药配合端面起爆,可在管内形成指数衰减形式的平面冲击波;理论模型与数值计算结果吻合较好,可给出冲击波超压峰值随距离的衰减关系,以及不同时刻冲击波的阵面位置。最后给出了该试验方法在水下爆炸加载典型结构件毁伤效应和流固耦合作用机理研究的应用场景。研究成果可为水下爆炸毁伤评估提供参考。

Centrifuge model tests of the formation mechanism of coarse sand debris flow

Using the self-developed visualization test apparatus, centrifuge model tests at 20 g were carried out to research the macro and microscopic formation mechanism of coarse sand debris flows. The formation mode and soil-water interaction mechanism of the debris flows were analyzed from both macroscopic and microscopic points of view respectively using high digital imaging equipment and micro-structure analysis software Geodip. The test results indicate that the forming process of debris flow mainly consists of three stages, namely the infiltration and softening stage, the overall slide stage, and debris flow stage. The essence of simulated coarse sand slope forming debris flow is that local fluidization cause slope to wholly slide. The movement of small particles forms a transient stagnant layer with increasing saturation, causing soil shear strength lost and local fluidization. When the driving force of the saturated soil exceeds the resisting force, debris flow happens on the coarse sand slope immediately.

某铅锌冶炼污染场地基于多源信息的重金属稳定化修复及其评价

冶炼污染场地土壤中多重金属复合污染的特征增大了对土壤的修复和最终利用的难度。本研究深入调查了某铅锌冶炼场地土壤重金属污染特征,针对性地制定多种联合稳定化修复方案,采用高精度混合装备添加药剂,实施稳定化修复工程。结果表明,Cd、Pb、Zn和As是场地土壤中最主要的重金属污染物,其中Cd、Pb、As的超标率分别为75.80%、76.43%、88.54%。重金属的分布模式与土壤理化性质、污染物迁移路径、水文地质条件、地层岩性、冶炼工艺、厂区功能布局等密切相关。土壤重金属污染主要来源于冶炼粉尘、废渣和废水排放等冶炼活动。稳定化工程效果显示,在药剂与土壤混匀程度不低于90%时,采用无机混合药剂与TJ400螯合剂的组合方案,对土壤稳定化处理7 d后,土壤中Cd、Pb和As同步稳定化效果最好。本研究结果可对多金属重污染场地土壤的稳定化修复提供实践指导。