Boussinesq equation-based model for flow in drainage layer of highway

In order to study the water flow in the drainage layer of highway under steady-state condition, one-dimensional （1D） Boussinesq equation-based model with Dupuit-Forchheimer assumption was established and the semi-analytical solutions to predict the water-table height were presented. In order to validate the model, a two-dimensional （2D） saturated flow model based on the Laplace equation was applied for the purpose of the model comparison. The water-table elevations predicted by ID Boussinesq equation-based model and 2D Laplace equation-based model match each other well, which indicates that the horizontal flow in drainage layer is dominated. Also, it validates the 1D Boussinesq equation-based model which can be applied to predict the water-table elevation in drainage layer. Further, the analysis was conducted to examine the effect of infiltration rate, hydraulic conductivity and slope of drainage layer on the water-table elevation. The results show that water-table falls down as the ratio of Is to K decreases and the slope increases. If the aquifer becomes confined by the top of drainage layer due to the larger ratio of Is to K or smaller slope, the solution presented in this work can also be applied to approximate the water-table elevation in unconfined sub-section as well as hydraulic head in the confined sub-section.

Application Analysis of Fine-grained Drainage Asphalt Surface Layer in Sponge Urban Road

With the overall progress and development of the market economy,the construction of sponge city has received extensive attention.To further create an environment more suitable for people’s lives,relevant departments should actively apply diversified materials and integrate material supervision mechanisms in the construction of sponge city roads,and construct a systematic road restraint mechanism and management system to ensure that the characteristics of the surface ecological environment can be fundamentally improved.This paper briefly analyzes the pavement structure design mechanism in combination with the engineering project.The application path of the finegrained drainage asphalt surface layer in the sponge city road is explained from the mix ratio of the mixture and the construction process.It is for reference only.

Fissure evolution and evaluation of pressure-relief gas drainage in the exploitation of super-remote protected seams

Based on nonlinearity contact theory and the geological structure of the Xieqiao Coal Mine in the newly developed Huainan coal field,rock movements,mining fissures and deformation of overlying strata were simulated by using the interface unit of FLAC3D to evaluate the pressure-relief gas drainage in the exploitation of super-remote protected seams.The simulation indicates that the height of the water flowing fractured zone is 54 m in the overlying strata above the protective layer.The maximum relative swelling deformation of the C13 coal seam is 0.232%,while the mining height is 3.0 m and the distance from the B8 roof to the C13 floor is 129 m,which provides good agreement with a similar experiment and in situ results.The feasibility of exploitation of a super-remote protective coal seam and the performance of the pressure-relief gas drainage in a super-remote protected layer are evaluated by comparisons with practice projects.It demonstrates that the relieved gas in the super-remote protected layers could be better drained and it is feasible to exploit the B8 coal seam before the C13 super-remote protected coal seam.The method is applicable for the study of rock movements,mining fissures and deformation of the overburden,using the interface unit to analyze the contact problems in coal mines.

Principle and engineering application of pressure relief gas drainage in low permeability outburst coal seam

With the increase in mining depth, the danger of coal and gas outbursts increases.In order to drain coal gas effectively and to eliminate the risk of coal and gas outbursts, we used a specific number of penetration boreholes for draining of pressure relief gas.Based on the principle of overlying strata movement, deformation and pressure relief, a good effect of gas drainage was obtained.The practice in the Panyi coal mine has shown that, after mining the C11coal seam as the protective layer, the relative expansion deformation value of the protected layer C13 reached 2.63%, The permeability coefficient increased 2880 times, the gas drainage rate of the C13 coal seam increased to more than 60%, the amount of gas was reduced from 13.0 to 5.2 m3/t and the gas pressure declined from 4.4 to 0.4 MPa, which caused the danger the outbursts in the coal seams to be eliminated.The result was that we achieved a safe and highly efficient mining operation of the C13 coal seam.

大华桥大坝坝顶结构设计创新与应用

大华桥水电站在坝顶结构设计过程中,改变传统的设计与施工思路,结合城市园林景观设计理念,对大坝坝顶防浪墙、照明、排水、配电房、铺装层等结构进行了创新设计,在设计上进行二次深化设计,在施工上进行小改小革,通过设计与施工的完美结合,不仅有效改善了坝顶排水、照明系统,解决了坝顶空间狭窄配电房无法布置的技术难题,还将坝顶打造成了一道靓丽的风景线。

多功能储层保护修井液在渤海油田的应用

渤海某油田X井主力开采沙三段,油层中部垂深2178.2 m,压力系数0.86,具有中低孔渗且非均质性强的物性特征。储层岩性以长石岩屑和长石细砂岩、含砾中粗砂岩为主,储层水敏伤害中等偏强,作业用水与地层水型不配伍,修井液大量漏失易导致水锁、水敏、无机垢沉淀等伤害。根据实际伤害类型,开发一种多功能储层保护修井液体系,使用无固相暂堵液降低修井液漏失,同时应用洗井助排液减小外来流体对储层造成的水锁、水敏、蜡堵等伤害,降低返排压力,缩短恢复周期。现场应用表明,该修井液体系可有效降低修井液漏失,且投产后原油产量在两天内恢复至作业前水平,表明其具有良好的储层保护效果,可有效缩短产能恢复周期。

Microstructures of surface modification layer on Q235 steel produced by laser melt injection of WC

WC powder was injected onto the surface of Q235 steel by laser melt injection (LMI). The influence of process parameters was studied. The microstructure and composition of the coatings were analyzed by SEM, XRD and EDS. The hardness and wear-resistant property of the coatings and Q235 steel were measured. The results show that LMI layer can be achieved only under the condition that process parameters meet the strict requirements. By optimizing the process parameter, excellent coatings can be acquired by injecting WC powder onto the surface of Q235 steel. The microstructure in the coatings is complex, which consists of WC, W2C and M6C(Fe3W3C-Fe4W2C) phases. The difference of Fe3W3C microstructure in different zones of the coatings is obvious. Both the compositions of the reaction layers around the particle and dendrite precipitation carbides in the upper coating are Fe3W3C. The average hardness of LMI layer is above HV 900, which is about four times that of Q235 steel. The friction coefficient of LMI layer is only one quarter that of the substrate, which indicates that the wear resistance of the coatings is enhanced sharply.

MICROSTRUCTURE AND MECHANISM OF A NEW TYPE OF Ni－Fe－W－P－S WEAR－RESISTANT BRUSH PLATING LAYER

A new type of Ni-Fe-W-P-S wear-resistant brush plating layer isdeveloped, and its microstructure is investigated at different temperatures by usingX-ray diffractometer, transmission electron microscope and surface analytical appa-ratus. The results revealed that the plating layer is composed of amorphous and mi-crocrystalline matrix and intermetallic compounds. Such a microstructure is verybeneficial to improving its wear-resistance.This new type of plating layer can replacethe chromium plating technique which is very poisonous for human health and harm-ful to the agricultural production.

To a forecasting of the wear-resistance of friction units details parameters question

The process of wear process expedient considering as set of special cases wear. For each special case wear were received settlement with reference to some certain conditions of experimental researches realisation, uniting in self SLOP. For successful application deduced dependence at forecasting wear-resistance the mechanism of reduction is developed which allows to distribute deduced dependencies to any conditions of wear process.

突出煤层分层切削钻孔瓦斯释放特征及应用研究

【目的】突出煤层钻进过程中的喷孔瓦斯超限是威胁矿井高效生产的安全隐患,分层切削钻进方法有助于在孔内削弱喷孔瓦斯压力,但分层切削形成的梯形钻孔周围瓦斯释放特征不明,限制了分层切削钻具结构设计和应用效果。【方法】以不同层间距、层厚差的分层切削钻孔为研究对象,建立数学模型分析钻孔周围瓦斯流动规律,并定量描述了分层切削钻孔瓦斯流量与层间距、层厚差之间的关系,在此基础上,通过数值模拟分析了分层切削钻具瓦斯释放调控机制,优化了分层切削钻具结构,并开展了现场钻进工业性试验。【结果和结论】结果表明:(1)多次切削成孔方式使钻孔的揭露面积逐渐增大,有效控制了瓦斯释放面积,进而调控了瓦斯释放流量,通过合理设计钻孔层厚差Hj与层间距Li,能够将瓦斯释放流量降低18.3%以上。(2)在一定层间距范围内,双层切削钻具调控效果将优于三层切削钻具,直径为63.5 mm刻槽阻尼钻杆在推力140 kN和扭矩4600 N·m作用下,最小安全系数为3.009,满足强度设计要求。(3)优选双层切削钻具,其揭露直径73 mm,终孔直径113 mm,层间距0.8 m,通过工业性试验,钻遇高压瓦斯富集区时,孔口瓦斯体积分数降低了37.7%,孔口瓦斯体积分数均未超过0.5%。表明分层切削钻具调控钻孔周围煤体瓦斯释放量、削弱瓦斯释放强度的作用显著,为预防钻孔喷孔瓦斯超限问题提供了新的解决思路。

长钻孔抽采条件下顶板瓦斯运移规律及减涌机理研究

顶板长钻孔瓦斯抽采是实现“以抽代巷”,实现顶邻近层瓦斯抽采,减少开采空间瓦斯涌出量的重要手段。结合顶邻近层瓦斯抽采减少回风顺槽上隅角瓦斯浓度工程实践,研究抽采条件下顶板瓦斯运移规律及其对工作面、回风顺槽瓦斯浓度涌出量减少作用机理,发现采用斜向高位钻孔群抽采造成的瓦斯压力降低区相互搭接,在回风顺槽顶板上方及左右两侧迅速形成1个沿巷道分布的低瓦斯压力区,该区域有效阻隔顶板瓦斯向回风顺槽的涌出;靠近采空区侧的顶板斜长钻孔对采空区瓦斯流动也有影响,可有效降低上隅角顶板附近瓦斯压力,降低瓦斯涌出量;抽采稳定后,工作面中部偏轨道顺槽一侧,仍会保有较高瓦斯压力区域,在工作面回采过程中应予以关注。

高突矿井未开采保护层区域瓦斯治理研究

为解决高突矿井试验工作面未开采保护层区域瓦斯浓度超限难题,基于COMSOL数值模拟分析了抽采参数对煤层瓦斯预抽效果的影响规律,通过物理相似模拟明确了采动卸压瓦斯导流通道。结合工程实际采掘进度,划分“掘进期”和“回采期”,分别开展瓦斯防治工作,采用立体式瓦斯抽采技术开展“顺层+穿层”钻孔瓦斯抽采。分析了掘进期高负压顺层钻孔与穿层钻孔的预抽效果,对比回采期断层附近穿层钻孔瓦斯浓度,研究了瓦斯抽采效果与工作面推进距离的关系。研究结果表明:不同布孔条件下,钻孔外侧瓦斯有效抽采半径在5 m左右,钻孔间距设置为10 m较为合理。掘进期,通过底抽巷施工穿层钻孔抽采邻近层瓦斯,配合顺层钻孔抽采使煤层瓦斯含量由24.37 m^(3)/t降至6.76 m^(3)/t,煤层瓦斯压力由1.62 MPa降至0.47 MPa;回采期,进风巷施工低负压高抽钻孔抽采上层采空区瓦斯,最大瓦斯浓度仅为8.7%。未开采保护层区域瓦斯抽采结合卸压瓦斯抽采技术成功消除了M18煤层的煤与瓦斯突出危险性。

玉米胚芽预榨饼浸出中湿粕脱溶的生产实践

在玉米胚芽预榨饼浸出制油过程中,湿粕脱溶是一个很重要的工序。基于玉米胚芽预榨饼的特点,对其浸出过程中湿粕脱溶工艺和设备进行了改进,并应用于生产实践。采用浸出器强制沥干和新型的高料层蒸脱机的技术方案,在强制沥干真空度1500 Pa、蒸脱机脱溶层净高3600 mm、脱溶时间35~40 min条件下,粕残溶达到650 mg/kg及以下,闪爆实验合格。通过采用新工艺和新技术,能在保证玉米胚芽粕产品品质的同时达到节能降耗的目的。

煤层气直井储层堵塞原因分析及解堵措施应用

针对煤层气直井储层堵塞后气量难以恢复的问题,开展了储层堵塞原因及恢复措施的研究。通过对煤层气直井储层堵塞成因及生产特征分析,将储层堵塞分为三种类型:层间干扰型、排采不连续型、井间干扰型,针对不同原因导致的储层堵塞在进行压裂车解堵时应根据各自的是适应性进行选井和施工,同时尽可能增大措施规模和排量,提高措施见效率和单井产气量。本文提供的压裂车解堵技术,能够有效解决储层堵塞问题,提高储层堵塞井单井产气量。

不透水土层地下室排水卸压抗浮施工技术

在不透水土层地区,土层中没有稳定的地下水,地下结构一般不采取抗浮措施,但近年来因地表水渗入肥槽引起的地下结构上浮时有发生,导致部分结构开裂,严重影响主体结构安全。以成都某小区为例,介绍了不透水土层地下室排水卸压抗浮施工技术,通过改造原有集水坑,将地下水收集并排至雨水系统,从而降低了水头,解决了地下室抗浮问题,可为类似工程施工提供参考。

Discovery of the Miocene Yuanmou Conglomerate and Its Significance for the Drainage Evolution in the Southeastern Tibetan Plateau

The active deforming southeastern margin of the Tibetan Plateau has developed series of fault basins filled with fluvial-lacustrine sediment deposited by drainage systems during every stage of its uplifting,the records of Cenozoic sedimentary sequence and detrital provenance in these basins are often obscure,making the interpretation of the drainage reorganization quite difficult.This research discovered the earliest Late Cenozoic fluvial conglomerate in the Yuanmou Basin,one of the fault basins in SE Tibet,and named the conglomerate as'the Yuanmou Gravel Layer(YMG)'.Clast petrography,morphology and paleocurrent directions of the YMG indicate that the conglomerate is the remain of a large paleo river traversing through the Yuanmou Basin from north to south.Detrital zircon U-Pb ages can imply the YMG has similar provenance areas with Anning,Dadu and Yalong rivers at age peaks of 175-275,600-1000,and 2100-2700 Ma,but the lack of the age peak of 30-100 Ma from Qiangtang Block implies that the paleo-river was not yet connected with the Jinsha River during the YMG's accumulation.The fluvial-lacustrine strata with gravel beds containing paleosimian fossils comparable to the YMG were deposited~7-11 Ma,further suggesting that the pre-formed south-flowing river was active during the Late Miocene.

复杂土壤分布特征及暗管排水响应模拟

盐碱地中障碍土层的存在可能会导致排水工程无法充分发挥其应有作用,这对其治理提出了很大挑战。以宁夏回族自治区红寺堡为研究区域,实地取样调查了不同点位的复杂土壤分布特征,基于HYDRUS二维模型分析了不同黏土层位置对于暗管排水流量的影响作用,并提出复杂土壤条件下的排水建议。结果表明,土壤存在弱透水层且无其他治理措施时,土壤盐分普遍偏高,弱透水层的位置不具有固定位置和特征,总体来说,弱透水层厚度以10~20 cm偏多。当黏土层位于暗管层时,10 cm黏土层就会导致暗管排水量减少20%,暗管上部10 cm位置处的黏土层对于暗管排水效果影响最大,较常规地下排水量减少22%;当黏土层位置超过2倍暗管埋深时,对于暗管排水量的影响较小。根据不同弱透水层的位置,合理设置排水排盐方式对盐碱地改良具有重要意义。

边坡水平排水管冻融排水试验研究

季节冻土区春季冰晶融化,边坡不断发生冻融滑塌工程灾害事故,造成重大经济损失。文中通过边坡水平排水管的冻胀融沉试验和冻融排水试验进行研究。研究结果表明,排水管应用在季节冻土区边坡工程中,优选75 mm直径PE排水管,施工布置密度为1根/m^(2),排水管仰斜角度为6°~8°,分析出多层水平排水管技术,并得到了此技术边坡稳定性的计算。研究可为减少寒区边坡冻融滑塌病害及提高边坡稳定性提供参考。

居住类建筑典型卫生间同层排水技术及经济性研究

通过建立居住类建筑典型卫生间各种同层排水方式的模型,就不同的同层排水方式进行技术及经济性对比。在同层排水技术中,采用排水汇集器和多通道地漏的不降板同层排水相比于传统的微降板、大降板和局部降板同层排水具有干区地漏水封不容易干涸的优势,并且前两者占用竖向空间小,相同条件下层净高更理想,但是不降板同层排水技术对卫生间布置具有一定的限制。同层排水的降板高度不同,土建本身的成本差别较小,不同同层排水方式的主要经济差别在回填材料以及防水材料用量上,不降板同层排水略显经济优势,更多的优势体现在技术上。

泄水抗浮技术在阿科太项目的研究及应用

随着城市化进程的快速发展,如何缓解城市资源匮乏,改善环境状况,提升居民生活品质是摆在当代建筑人面前的一大难题。人们对地下及地面空间高效开发利用的需求达到了前所未有的高度,由此而衍生的建筑结构抗浮问题日益突出。常用抗浮方法主要是采用抗拔桩及抗浮锚杆,此类施工方法均存在造价高、施工周期长、锚杆(索)易腐蚀、抗拔桩检测困难、底板水压荷载过大等问题,因此,客观上需要有更好的抗浮解决方案。文中以深圳市宝安区阿科太老年公寓项目为研究背景,从抗浮设计及现场施工两个方面详细阐述了泄水抗浮技术在该项目的应用,并结合实际应用效果,认为泄排水抗浮是一种节材、节能的绿色抗浮工艺和方法,同时是一种经济合理、可行的施工方法。