某铅锌尾矿库对地下水环境影响及防治措施

铅锌尾矿的浸出液中含有重金属等对地下水环境有重要影响的污染因子。利用地下水数值模拟专业软件GMS,结合研究区水文地质条件,对不同工况下地下水环境的影响程度及范围进行模拟计算。结果表明,达到Ⅱ类工业固体废弃物处置场规定的防渗要求条件下,尾矿库运行浸出液下渗量有限(2.8 m3/d),并不会使区域地下水超出《地下水质量标准》Ⅲ类标准,而防渗层仅出现10%破损时,浸出液下渗量为(97.22 m3/d),使地下水下游方向50 m内地下水中Pb超出Ⅲ类标准,超标范围约0.0375 km2。反映出该类处置场中的防渗措施是对地下水环境保护的重要保证。     

One year irrigation experiment to assess losses and runoff volume relationships for a residential road in hertfordshire,England

Six sections of a residential road (75 mm bituminous macadam over 200mm lean mix concrete over 100 mm hoggin with a recent surface dressing of 10 mm granite chippings and K1-70 binder) that drain to individual instrumented gully pots were irrigated along the kerb and then over the whole road approximately monthly for a year. The aim was the determination of terminal infiltration losses, initial losses, percentage runoff, and infiltration curves for the kerb and road surface. The results were not as expected from the literature. There is an annual cycle of infiltration losses at the kerb with a winter peak caused by frost action that is 3.2 times greater than the terminal loss rate at kerbs in summer. The terminal loss rate for an ‘average catchment’ was 6.4251 min^?1 from the road surface and 14.251 min^?1 in summer and 46.281 min^?1 in winter at the kerb. Evaporation was usually more than an order of magnitude less significant than infiltration. The wide variation in initial losses before runoff commenced was inexplicable. Two sections of road behaved in the classic manner with initial losses averaging 0.8 mm, two other catchments had highly variable initial losses in the range 1.2 to 8.8mm, and the last two pieces of road were even more erratic. The percentage runoff for those irrigations of over 15 mm of equivalent rainfall was never more than 10 per cent. The maximum per cent runoff was around 50 per cent following 10 mm of equivalent rainfall for kerbside irrigation and only 5 mm of irrigation over the whole road. There were no significant simple or multiple regression relationships between percentage runoff from the kerb or the whole road irrigations and irrigation amount, slope, UCWI, and SMD. Infiltration curves, for kerb and road irrigation, were so diverse that they do not represent the ‘simple impervious surfaces’ envisaged at the start of the experiment and described in the literature. Since the artificial irrigation of kerbs and roads has failed to substantiate existing theory, these experiments should be repeated at a variety of sites with a high rate of irrigation.     

典型隔水边界非稳定流承压含水层抽水试验研究

隔水边界附近的承压含水层,即半无限区域的承压含水层参数的准确求取对于特定地段的地下水资源量计算具有重要意义。以高密市柴沟镇小于家庄抽水试验为例,详细阐述了隔水边界附近的承压含水层参数求取过程,并对结果进行较为详尽的讨论。     

SCOUR AROUND GROINS

l INTRODUCTIONGroins are smictures consmicted transverse to the river flow and extended from the bank into the river.They serve one or more of the following functions: 1) training of the stream flow, 2) protection of s treambank frOm erosion, and 3) imProvement of flow dePth for navigation. Groins, according to method andtyPe of construction material, are usually classified as permeable or imPermeable. However in this paPeranother wne is introduced, i.e. semipermeable groin, which is th…     

论L花岗岩体与3701铀矿床的成因联系

矿床赋存于L花岗岩体外接触带(0—120m)的碳酸盐岩中,矿化围岩为中泥盆统应堂组泥质灰岩。矿体呈透镜状或似层状,属细脉浸染型矿化。矿化可分为四个阶段。工业矿物为沥青铀矿,呈显微浸染状、显微脉状分布于方解石中,或充填、交代伴生矿物。脉石和金属矿物主要有方解石、黄铁矿、方铅矿、闪锌矿、黄铜矿和砷黝铜矿等。矿脉两侧的围岩呈现面型和线型弱热蚀变。L花岗岩体出露面积238km~2,为一个单阶段侵入岩基,其岩性主要是粗-中粒黑云母花岗岩。鉴于铀矿化年龄(65.0一30.7 Ma)较L花岗岩体成岩年龄(318一202 Ma)小得多,因此可认为矿化与花岗岩浆活动无成因上的联系。但花岗岩在下列方面对3701铀矿床的形成起重要作用:提供铀源和错:为矿化提供少量硫、碳和微量元素;形成有利于含铀溶液集聚的隔水底板;为加热含矿溶液和促使其对流循环提供部分热源.     

Deformation of multi-directional random waves passing over an impermeable submerged breakwater installed on a sloping bed

This study investigates the wave deformation of multi-directional random waves passing over an impermeable submerged breakwater installed on the slope. Experiments were conducted in a three-dimensional wave basin equipped with a multi-directional random wave generator. Measurements of the free surface elevations around an impermeable submerged breakwater were carried out using 19 capacitance-type wave gages. In addition, a numerical model is proposed in three-dimensional random wave field. It is shown that the numerical results reproduce the general trend of the experimental results well. Investigations are made to study the effect of the spreading parameter S_max and bottom topography (bottom slope and submerged breakwater) on the wave deformation. It is pointed out that concentration of wave energy with larger values of the spreading parameter S_max is located within narrow limits in onshore side of the submerged breakwater. Furthermore, the supplementary discussion is made by means of numerical results.     

Geotechnical characterization of carbonate marls for the construction of impermeable dam cores

Fine-grained, more or less cohesive carbonate materials are extremely widespread in terms of surface area and are, therefore, commonly used as materials to construct impermeable cores for dams. However, it has not been adequately documented whether the carbonate content in fine-grained soils significantly affects their engineering behaviour. The present study shows that the carbonate content substantially influences the engineering behaviour of clayey material. For this, we subjected 32 samples to different laboratory tests, such as the normal Proctor, the Atterberg limits, granulometric analysis, oedometric and undrained triaxial tests. The resulting parameters were correlated with the carbonate content of the samples.

The materials studied in this work had been used in the construction of the impermeable core of the San Clemente Dam, belonging to the hydrographic basin of the Guadalquivir River (southern Spain). These marls present, as their prime characteristic, a carbonate content of the fine fraction consistently exceeding 50%, giving them special importance in the study of this phenomenon.

In this study, a direct relationship was found between the geotechnical properties of the soils studied and their degree of compaction, with the carbonate content and the type of minerals in the clay being the main factors determining the behaviour of these soils. Finally, we conclude that the percentage of carbonates should be used as a classification criterion for the soils used to construct the cores of earth-filled dams.     

透水与隔水夹层对粉质土液化影响试验研究

黄河三角洲沉积物以粉质土为主,循环荷载作用下隔水夹层与透水夹层的存在对粉质土孔压累积、消散及液化的影响如何,目前尚不清楚。本文针对4种隔水夹层与透水夹层的组合情况,利用现场原位振动和室内土样振动试验,研究隔水夹层与透水夹层的存在对循环荷载作用下黄河口粉质海床土液化过程影响,发现循环荷载导致黄河三角洲粉质土孔隙水压力、粒度成分、密度、含水量及孔隙比等物性指标发生的变化,因夹层的不同有明显的差异,并且其液化性能因夹层结构的不同而不同,有透水夹层时,相对提高了粉土的抗液化性能,隔水夹层则相反。     

尼泊尔波迪科西水利枢纽三维渗流分析

针对尼泊尔波迪科西水电工程首部枢纽布置和软土坝基的岩性条件和渗透特征 ,通过对混凝土防渗墙深度、灌浆帷幕长度、混凝土渗透性、地基渗透性的敏感性分析 ,确定出防渗墙和防渗帷幕的优化方案 ,并对三种库水位工况下的三维渗流场进行了详细的计算分析 ,为工程优化设计提供依据.     

Dynamic pressures and forces exerted on impermeable and seaside perforated semicircular breakwaters due to regular waves

The semicircular breakwater (SBW) is a composite breakwater consisting of a semicircular caisson resting on a rubble mound. The SBW function as a barrier dissipates the incident wave energy and creates tranquillity on its leeside. The dynamic pressures due to regular waves exerted on seaside perforated SBWs with 7 and 11% of exposed surface area with perforations were measured. The measured pressures are compared with those exerted on impermeable SBWs. In addition, the forces exerted on the caisson alone are measured. The reflection coefficient, measured total forces on the caisson of the models, and the pressures are presented as functions of relative water depth. The effect of the water depth and the percentage of perforations on the above stated variables are examined, details of which are reported in this paper.