工艺参数对页岩砖表面氡析出率的影响

采用活性炭坌法吸附页岩样品砖（在不同工艺参数条件下制备）表面析出的氧气,运用高纯锗探测器测量氡子体214Pb特征峰射线的计数．得出页岩样品砖表面氡析出率。通过比较,分析出不同工艺参数（煤矸石的含量、负压、焙烧温度）对页岩砖表面氡析出率的影响。     

聚合物对透水性混凝土性能的影响研究

研究了不同水灰比和聚合物掺量对透水性混凝土的强度、抗冻性、透水系数的影响,结果表明,透水性混凝土存在最佳水灰比;同时聚合物的加入,可显著提高透水性混凝土的抗折强度、抗压强度以及抗冻性能,但对透水系数的影响较小。     

土体参数对支护桩水平位移的影响分析

随着我国经济的快速发展,房屋建筑体积和高度都在不断增加,深基坑工程采用排桩支护或者是桩锚支护的也越来越多,结合实际工程,重点分析了影响桩体水平位移的几个重要因素,分别是土体的弹性模量、重度和内摩擦角,通过分析可知,桩体水平位移随着土体弹性模量的增加而减小,随着重度增加而增加,且影响较明显,随着内摩擦角增大而减小。这些分析为以后的工程设计提供了参考,有着重要的现实意义。     

Seasonal variations in soil gas radon concentration

We have been studying seasonal variations in soil gas radon concentration in southern Finland since 1982.To detect the radon we employ liquid scintillation solution in an open glass vial placed in a plastic tube set in a hole drilled in the ground.The results from an esker area show that there may be an appreciable seasonal variation in soil gas radon concentration, similar to that in houses. Because of the varying permeability and radium concentration of the ground, small changes in the building may have a large impact.     

气象参数对成都地区办公建筑能耗的影响及预测

气象参数是影响建筑热环境和供暖空调能耗的主要因素之一。基于成都地区1971—2000年共30a的历史观测数据,生成了建筑能耗模拟软件EnergyPlus所需要的逐时气象数据文件。比较分析了该地区30a干球温度、太阳辐射等各气象参数月均值的变化,模拟分析了该地区建筑的采暖、制冷及总能耗,利用多元回归建立了建筑能耗与气象参数之间的关系式,并检验了该关系式的准确性。结果表明:成都地区办公建筑能耗变化与各气象参数没有呈现明显的规律性;建筑月总能耗与各气象参数呈纯二次多项式关系,月采暖能耗、月制冷能耗与各气象参数呈交叉二项式关系;建筑月能耗回归模型能够较准确地预测建筑月能耗与各气象参数的关系,且月采暖能耗和月制冷能耗回归模型预测的准确性优于月总能耗模型。     

电子氡检测仪测定土壤中氡浓度方法的研究

本文使用RAD-7型电子氡检测仪测定土壤中氡浓度,提出了防止检测系统漏气的措施,优化了仪器运行的各种参数,建立了自动化检测系统,是一种快速、准确、简便的测定土壤中氡浓度的方法。     

The influence of pH on phosphate release from lake sediments

pH is believed to be an important regulating factor for the release of phosphate from freshwater sediments. Usually, this is demonstrated in laboratory experiments using intact sediment cores and pH regulation of the overlying water by means of NaOH additions. This technique and a pH regulation technique by means of CO₂-stripping were compared. The first method resulted in a 10-fold increase in release rate at pH 9.5 compared to the rate at pH 8.3. The stripping technique yielded only a doubling of the release rate at pH 9.3. Measurements of pH profiles in the sediment in experiments performed at pH 8.3 and 9.0 proved that the enhanced phosphate release when using NaOH for pH regulation is mainly an artifact caused by an increased alkalinity in the water column and the upper sediment layers, resulting from the NaOH additions.     

土质路基双块式无砟轨道参数影响分析

针对土质路基双块式无砟轨道结构,建立了双块式无砟轨道整体有限元模型,研究了主要参数变化对无砟轨道受力的影响,确定了无砟轨道设计参数,从而确保无砟轨道结构设计的安全性、经济性。     

Settlement trough parameters for tunnels in Irish glacial tills

Glacial till (or boulder clay) is the most widespread sediment on the island of Ireland. The behaviour of these tills, especially Dublin Boulder Clay, is now better understood as a result of ground investigations and associated testing for major construction projects, particularly in the east of the country over the past decade. Despite an increase in tunnelling activity in the country over the same time period, there is very little documented evidence on the settlements induced by tunnelling operations in glacial till. In this paper, transverse surface settlement data from two glacial till sites are presented. Four profiles are presented for the ‘soft ground’ TBM-bored section of the Dublin Port Tunnel. Nine profiles are reported for pipe-jacked microtunnels constructed for a sewerage scheme in Mullingar in the Midlands; one of which was measured at the top of a railway embankment under which the pipeline passes. The measured settlements have been interpreted using a standard Gaussian error function, and trough width parameters show dependence on the fraction of the till, fine or coarse, that governs its behaviour. In addition, conservative design estimates of maximum trough settlement and volume loss have been provided, and the impact of boulders is discussed. This paper provides the first empirical guidance for predicting surface settlements above tunnels in Irish soils.     

渗透型涂料表面防护对钢筋锈蚀的影响

采用半电池电位法研究了持续氯盐侵蚀和干湿循环条件下,不同水灰比、表面防护与未防护混凝土中钢筋锈蚀的发展规律.结果表明,当水灰比从0.4增大到0.6,混凝土内钢筋的锈蚀速率增大了约2倍;水灰比相同时,应用硅烷防水剂进行表面防护,混凝土的锈蚀速率明显小于未防护混凝土,且表面防护对于已出现钢筋锈蚀的混凝土依然有效.因此,表面防护是提高和改善新建及既有混凝土结构耐久性的有效措施.     

Variation in residential radon levels in new Danish homes

Radon‐222 gas arises from the radioactive decay of radium‐226 and has a half‐life of 3.8 days. This gas percolates up through soil into buildings, and if it is not evacuated, there can be much higher exposure levels indoors than outdoors, which is where human exposure occurs. Radon exposure is classified as a human carcinogen, and new Danish homes must be constructed to ensure indoor radon levels below 100 Bq/m³. Our purpose was to assess how well 200 newly constructed single detached homes perform according to building regulations pertaining to radon and identify the association between indoor radon in these homes and municipality, home age, floor area, floor level, basement, and outer wall and roof construction. Median (5–95 percentile) indoor radon levels were 36.8 (9.0–118) Bq/m³, but indoor radon exceeded 100 Bq/m³ in 14 of these new homes. The investigated variables explained nine percent of the variation in indoor radon levels, and although associations were positive, none of these were statistically significant. In this study, radon levels were generally low, but we found that 14 (7%) of the 200 new homes had indoor radon levels over 100 Bq/m³. More work is needed to determine the determinants of indoor radon.     

The influence of soil remediation on lead in house dust

Lead in house dust has long been recognized as a principal source of excess lead absorption among children at the Bunker Hill Superfund Site (BHSS) in northern Idaho. House dust lead concentration from homeowner's vacuum cleaner bags has been monitored since the epidemic of childhood lead poisoning in 1974. Geometric mean house dust lead concentrations decreased from >10000 mg/kg in 1974 to approximately 4000 mg/kg in 1975, in response to air pollution control initiatives at the defective primary lead smelter. After smelter closure, 1983 mean dust lead concentrations were near 3000 mg/kg and were most dependent on soil sources. Following emergency soil removals from public areas and roadsides and fugitive dust control efforts in the mid-1980s, house dust lead decreased by approximately 40-60% to 1200-1500 mg/kg. In 1992, a cleanup goal of 500 mg/kg dust lead community average, with no individual home exceeding 1000 mg/kg, was adopted. This goal was to be achieved by a combination of contaminated soil removals and fugitive dust control efforts throughout the 21 square mile BHSS. Continual reductions in house dust lead concentrations have been noted throughout the residential area soil cleanup. Geometric mean house dust lead concentrations averaged approximately 500-600 mg/kg from 1996 to 1999 and dropped below 500 mg/kg in 2000. Analysis of these data indicates that approximately 20% of the variance in dust lead concentrations is attributed to yard, neighborhood, and community soil lead concentrations. Since 1996, dust lead concentrations and dust and lead loading rates have also been measured by dust mats placed at entryways into the homes. Neighborhood soil lead concentrations, household hygiene, the number of adults living in the home, and the number of hours a child spends outdoors in summer explain approximately 26% of the variance in mat dust lead loading rates. It is estimated that post-remedial house dust lead concentrations will stabilize at 400-500 mg/kg, as compared to approximately 200 mg/kg in socio-economically similar background communities; the difference possibly attributed to residual soil concentrations (3-6 times background), recontamination of rights-of-way, tracking of non-residential mining district soils and dusts, fugitive dusts associated with the remediation, and residual structural or carpet dusts.     

Radon and radon daughter levels in energy efficient housing

radon and radon daughter concentrations have been measured in 33 “energy-efficient” homes in a small subdivision in Kanata, Ontario. Integrated radon measurements were determined over three month periods for a year using solid state nuclear track detectors. Radon and radon daughter grab sample determinations were made during corresponding periods and confirm the distributions of the integrated radon measurements.Annual average individual home radon concentrations show an 8 fold concentration range between homes. This variability in radon concentrations is not reflected in the range of air exchange rates for the homes. A distinct seasonal variation is noted for the median values of the radon and radon daughter concentrations and the equilibrium factor F in the dwellings.     

降雨入渗对震后边坡岩土力学参数影响

通过对震后重灾区平通镇牛斐村大咀山山坡土样进行直接剪切试验,探讨了降雨对山坡土体的抗剪强度影响因素,并对正交试验结果进行了分析,得出了一些有益的结论。     

Investigation of the relation between meteorological parameters,North Atlantic Oscillation and groundwater levels in Torbali Region,Turkey

Groundwater, the most reliable fresh water source, is used for drinking, domestic and agricultural purposes. Thereby, understanding its behaviour is important for the sustainability of groundwater sources. In this study, relations between the trends of climate parameters [recharge depending on precipitation, temperature and North Atlantic Oscillation Index (NAOI)] and groundwater levels trend were investigated for Torbali Region in Turkey. The human impact that is one of the deterministic components on the groundwater level has been removed from the groundwater level data sets. An increasing trend was observed in the early 1990s, and turning points were determined by using paired t‐test. The trends of the groundwater levels indicate that climate parameters affect groundwater levels in the similar manner. According to the results of the analyses, it is revealed that there is a similar linear variation that is strong and inverse between the trends of NAOI and meteorological indicator (temperature and recharge) and groundwater level.     

天津地区地基土中氡含量的初步调查

在天津市域内选择适宜地点实地测量,从目前仅有的30余点实测资料统计,天津市土壤氡的平均浓度为8 572 Bq/m3。根据氡及其短寿命子体的形成、衰变、运移、富集规律以及实测结果得出,天津市域内的断裂经过地带以及凹陷地区,如蓟县、宁河、宝坻、武清、汉沽、市区及塘沽的海河沿线地区,氡浓度较高。     

The occurrence of methane in recent deltaic sediments and its effect on soil stability

Summary River-mouth depositional pattern are modified by sediment-deforming processes of sufficient magnitude to severely endanger bottom-supported structures. Several types of deformations are present, including (a) peripheral slumping, (b) differential weighting and diapirism, (c) radial tensional faulting, (d) mass wasting and flowage induced by wave motion and degassing, and (e) deepseated clay flowage. The processes of bacterial methane production and the resulting effects on sediment deformation have been investigated in four cores taken in the Recent deltaic sediments of the Mississippi River. Dissolved methane in the interstitial waters ranged in concentration from 2 × 10⁻³ to 1.7 ml/l, whereas total CH₄ (dissolved plus bubble phase) ranged from 5 × 10⁻³ to over 300 ml 1. High concentrations of methane corresponded to zones of low shear strength and were observed where dissolved sulfate was depleted. Calculations of maximum in situ methane concentrations, based on chemical reduction of excess total CO₂, indicate that methane could be present above saturation levels (bubble phase). Classical anaerobic geochemical gradients were observed in sediment profiles where no movement had previously occurred. The pore water geochemistry of sediment profiles within peripheral mudflows suggest that coexistence of methane and sulfate indicate convective mixing of sediments and bottom seawater. Calculations using the equilibrium slopes of wave-induced mudflows indicate that shear strengths during movement must be less than the values measured before or after the flow. An improved model of mass movement is presented which relates the physical and geochemical properties of unstable sediments.

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La Présence De Méthane Dans Des Sédiments Deltaiques Récents Et Son Influence Sur La Stabilité Du Sol

Résumé Les structures des sédiments à l’embouchure d’un fleuve sont modifiées par des processus déformateurs d’une ampleur suffisante pour mettre gravement en danger les constructions qui s’appuient sur le fond. On peut distinguer plusieurs types de déformations: a) enfoncement périphérique; b) tassement irrégulier et diapirisme; c) formation de failles de tension rayonnantes; d) perte de masse et écoulement provoqués par le mouvement des vagues et le dégazage; et e) écoulement d’argiles profondes. Les processus de production du méthane par les bactéries et leurs conséquences sur la déformation des sédiments ont été étudies sur quatre carottes prélevées dans les sédiments delta?ques récents du Mississipi. Les concentrations de méthane dissous dans les eaux intersticielles sont comprises entre 0,002 et 1,7 ml/l, cependant que le méthane total (bulles et gaz dissous) est compris entre 0,005 et plus de 300 ml/l. Les fortes concentrations en méthane correspondent aux zones de faible résistance au cisaillement; elles s’observent aux endroits où le sulfate dissous est épuisé. Les calculs de concentrations maximales de méthane in situ, basés sur la réduction chimique du CO₂ total en excès, montrent que le méthane pourrait être présent au-dessus des niveaux de saturation (phase bulles). Les gradients géochimiques anaérobiques classiques furent observés sur des profils sédimentaires où aucun mouvement n’était apparu précédemment. La géochimie des eaux intersticielles des profils sedimentaires des coulées de boues périphériques permet de supposer que la coexistence de méthane et de sulfate indique un mélange de sédiments et d’eau du fond de la mer, par convexion. Les calculs utilisant les profils d’équilibre de coulées de boues produites par les vagues montrent que la résistance au cisaillement pendant le mouvement peut être moindre qu’avant ou après l’écoulement. On présente un modéle amélioré de mouvement de masse, tenant compte des propriétés physiques et géochimique des sédiments instables.

     

原始气象数据对建筑设计室外计算参数的影响

根据暖通规范的室外空气计算参数的确定方法,对1971年~2000年的原始气象资料进行了统计计算,将得出的室外空气计算参数与暖通规范中的室外空气计算参数进行了比较分析,结果表明室外空气计算参数总体呈上升趋势。     

The influence of calculation error of hourly marine meteorological parameter on building energy consumption calculation

The ocean is a crucial area for future economic development. The marine environment has high energy-efficient and ecological requirements for building construction. Meteorological parameters are the key basis for the analysis and design of building energy efficiency. The lack of meteorological parameters for energy efficiency, particularly hourly data, under oceanic climatic conditions is a universal problem. The appropriate calculation methods of hourly meteorological parameters under oceanic climatic conditions are explored in this study. The impact of the calculation errors of the hourly meteorological parameters on building energy consumption is also analyzed. Three key meteorological parameters are selected: temperature, humidity, and wind speed. Five hourly calculations methods, including linear interpolation, cubic spline interpolation, pieceated three-Hermite interpolation, Akima interpolation, and radial basis function interpolation, are selected to calculate the error of the difference method, with Xiamen, Haikou, and Sanya as the locations of meteorological research. Appropriate interpolation methods are selected for the three parameters, and the seasonal and regional characteristics of the errors of each parameter are compared. Different interpolation methods should be selected for different meteorological parameters in different seasons. The error data of the three parameters of different magnitudes are constructed. A quantitative relationship between the sum of squares due to error of the three meteorological parameters and the rate of change of cooling energy consumption is established. The hourly calculation errors of meteorological parameters have an important impact on the calculation of dynamic energy consumption. The energy consumption differences caused by the errors of different parameters are significant. Obvious regional and seasonal differences also exist. This research strengthens the research foundation of building energy consumption calculation under oceanic climate conditions.