浅析除险加固高压旋喷灌浆质量问题与对策

通过对高压旋喷灌浆施工技术的特点、流程及施工质量控制、工艺要求等进行探讨,对高压旋喷灌浆施工质量问题进行分析并提出相应对策;为确保工程质量,高压旋喷灌浆应严格按照技术要求进行操作,重点对水压、水量、气量、浆液密度、进浆量、提升速度、回浆密度进行控制。通过具体项目实施,结果表明:高压旋喷注浆施工质量问题通过采取措施是能有效控制的,高喷灌浆对坝体防渗堵漏效果好,对类似的坝体防渗加固工程具有借鉴作用。     

旋管机设计制造及应用分析

<正>旋管机制作混凝土排水管,从技术上解决了东北地区混凝土抗冻要求。正常混凝土C20水灰比0.56左右,而用旋管机制作排水管混凝土水灰比0.35左右,减少用水量35%,经过工作轴碾压,孔隙率减少,密度增大,抗渗效果增强,抗压强度增加,抗冻能力大大提高,在辽西北地区抗冻工程可广泛应用。研究设计制造的混凝土旋管机,运行状况良好,制作的Φ1 500mm、Φ1 000mm、     

水平旋喷桩在湿陷性黄土隧洞涌砂段施工浅析

引洮供水一期工程总干渠7号隧洞,涌砂段桩号为60+572.00～61+079.42,围岩类型为第三系临夏组疏松砂岩,具有成岩差、欠固结、胶结不均等特点,其天然密度为2.21 g/cm3。文章在介绍水平旋喷桩超前预支护的原理及特点基础上,阐述了旋喷桩超前预加固方案,以及旋喷桩施工工艺、技术参数和注意事项等,有效地防止了隧道挖掘和施工中出现地层变形,起到了止水和加固性作用。     

浅析高压旋喷桩在软基渠道扶壁的应用

黔中水利枢纽一期工程桂松干渠软基渠道采用高压旋喷桩进行扶壁,通过芯样检测和现场挖桩试验,表明采用高压旋喷灌浆后提高了基础的密度,降低了含水量,大幅度提高了软基的抗剪断强度,确保了软基渠道开挖后的稳定性,为渠道进行混凝土箱涵施工创造了条件,同时为在第四系淤泥质黏土进行渠道施工积累了丰富的经验。     

高压旋喷桩在某水库大坝除险加固中的应用

高压旋喷桩在某水库大坝除险加固中的应用,介绍了高压旋喷桩的设计方案、施工工艺及其注意事项、检测方法,检测结果表明该工程采用高压旋喷桩除险加固效果良好。     

高压旋喷灌浆技术在急水坝防渗加固中的应用

通过广西宾阳县露圩镇急水坝的高压旋喷灌浆施工,对土坝高压旋喷灌浆的布孔、灌浆、质量控制进行了论述,探讨高压旋喷灌浆技术在土坝防渗加固工程中的应用效果及前景。     

XZQ-Ⅱ型旋斗式自动清污机

拦污栅前的污物分布杂乱,通常都是被动地由清污机具给予强制清除.旋斗式自动清污机的旋斗,运行时在水下形成局部挡水所转化成动能的能量,加上斗前流动水层中的能量,通过旋斗的特定边界,继而使旋斗内部产生足够强度的螺旋流;栅面被旋斗覆盖的水层,产生了局部的水流倒流现象,栅面上的污物向上游旋斗内流去,"主动"地进入旋斗.在污物堵塞达到一定程度时,能自动完成清污、卸污和送污.XZQ-Ⅱ型旋斗式自动清污机的样机,投入运行验证后,进行了验收,受到有关专家的肯定.1994年获国家专利.     

旋喷桩在九龙江北溪引水左干渠改造二期工程土洞施工中的应用

该文结合工程实例,介绍旋喷桩在土洞施工中的应用,阐述了旋喷桩的参数选定和施工工艺等,实施效果验证了旋喷桩在土洞施工中的应用优势,可供类似工程借鉴。     

圆管螺旋流继旋器的初步试验研究

继旋器也是一种局部起旋器,是起旋器的延伸。当起旋器后流场的切向速度不能将所需输送的颗粒有效的“抬托”,此时就需要继旋器来继续加强水流旋转作用。对继旋器的预旋与起旋作用进行了试验研究,并根据起旋器的研究方法计算出继旋器的起旋效率。     

高压旋喷灌浆在黄沙溪水库大坝除险加固中的应用

文章对黄沙溪水库大坝的工程概况作了说明,分析了高压旋喷灌浆在该大坝除险加固工程中的应用,并介绍了高压旋喷灌浆的施工流程、施工方法,并对施工过程出现的问题提出了解决措施。高压旋喷灌浆在黄沙溪水库除险加固工程中应用于大坝防渗上取得了较好的效果。     

INSTABILITY OF GAS/LIQUID COAXIAL JET

In this article the emphasis was given to the discussion of the effects of diameter ratio and swirling on instability character for the gas/liquid coaxial jet used by Liao, et al.[1]. The results indicate that the finite diameter ratio markedly increases the maximum growth rate, the most unstable wavenumber, as well as the cutoff wavenumber. It implies that the finite diameter ratio will lead to the liquid jet breakup length shorter and the liquid drop size smaller. The effect of the swirling jets is much more complex:for the axisymmetric perturbation mode, the swirling enhances the flow stability, for helical perturbation, the dominant instability mode occurs at n<0. And it is found that in long wave region there exists a new kind of instability modes at n=1 that was not mentioned in Liao et al.'s article. For this new mode, there appears a dominated swirling ratio at which the flow has the maximum growth rate.     

高水头大流量泄洪洞内消能工研究进展

为了降低工程投资,提高泄洪安全,防止出口冲刷、雾化和高边坡不稳定现象,近20年来国内外对各种内部消能的泄洪洞进行了研究,部分成果如旋流竖井(洞)、孔板(洞塞)和消力井等内部消能工,已应用到实际工程中。本文对这几种内部消能工的应用条件、消能效果和运行的可靠性进行了比较研究。认为旋流式和消力井式消能工适用于下游水位较低的条件,前者采用连续旋转和扩散消能,消能率高,掺气充分,可有效防止发生空蚀;后者采用井内集中消能,相对而言消能率较低。而孔板(洞塞)式消能工适用于下游高水位条件,其消能率较低,同时为了避免洞内发生高压不稳定气团流动,进水口闸门必须控制在高库水位运行。比较而言旋流式泄洪洞具有较大的优越性。     

竖井式水平旋流洞含气水流模型相似律

针对竖井水平式旋流洞通气孔模型试验中通气量和掺气水流的含气率在进行原型数据换算中存在的问题,考虑到空气可压缩性,通过对气液两相流基本方程的相似理论研究,导出原模型的力学相似律.在进一步研究竖井水平旋流洞模型相似律的基础上,推导出竖井式水平旋流洞原、模型通气管截面积的换算关系和原、模型含气率分布的换算关系.将所得理论公式应用于公伯峡水电站竖井式水平旋流式泄洪洞模型试验,并为原型观测结果所证实.     

旋流喇叭形竖井泄洪洞水力学机理及应用

改变传统的防漩消涡观念,研究出一种带有潜水起旋墩的新型喇叭形竖井泄洪洞,在各种水头下均能产生稳定的空腔旋转流运动,用以消除溢流堰和竖井的负压,避免发生空蚀,同时提高泄洪洞的消能率。潜水起旋墩同喇叭形堰外缘的切线成小角度连接,其旋流运动机理是,当水流漫溢堰顶时,开始产生旋转流,而当水深超过起旋墩顶时自动扩大入流角度和加大泄量,在底层旋流的拖曳下作同步强力旋转流运动。所提出的设计理论和试验研究成果已应用到广东清远抽水蓄能电站的竖井泄洪洞设计中。     

体型参数对旋流排沙渠道水沙特性的影响

为明确关键体型参数对渠道和排沙洞内水沙特性的影响,在模型试验研究的基础上开展了旋流排沙渠道的水沙两相流数值模拟。结果表明:起旋室高度对截沙率影响较为显著,最大相差5.41%;排沙洞直径、倾角和起旋室出口宽度对分流比影响显著,最大相差8.13%,增大倾角后改善了原排沙洞封闭端因壁面条件影响而产生的泥沙淤积;起旋室出口宽度对渠道内水沙特性基本无影响;不同体型下旋流排沙渠道均可高效、持续排沙,截沙率均大于90%,经过起旋室后,高含沙水流从排沙洞流出,下游渠道含沙量急剧减小。     

THEORETICAL AND EXPERIMENTAL STUDY ON THE CONICAL SWIRLING WATER JET FLOW

This paper is concerned with theoretical and experimental study on theconical swirling water jet flow.Based upon the theoretical analysis,the experiment on thestructural characteristics of swirling water jet flow including the velocity and pressure dis-tribution laws,on which the parameters of the jet,nozzle and directional blades havemore or less influence,was carried out in CSSRC by using a 3-D LDV in order to optimizea new high-efficiency jet instead of swirling drilling bit for rock-breaking and continuouslydrilling,and to meet the demand of radial horizontal drilling technology.Meanwhile basedon the experimental results,the numerical simulation was conducted for the conicalswirling water jet in the immersed well-bottom flow by solving the RANS equations in the3-D body-fitted coordinate system with the k-ε turbulence model.The numerical resultsare consistent with the experimental data,and lead to some conclusions which are impor-tant for applying the conical swirling water jet to the petroleum drill     

固粒分区存在的旋转射流场稳定性研究

本文由理论分析得到了三种固粒存在形态下旋转射流失稳模型的扰动增长率及相关修正瑞利稳定性准则，根据该准则，对三种不同固粒存在形态下气一固流动模型在不同扰动性质和固粒属性下，由计算得到了对应的增长率曲线，给出了固闰属性及扰动央求充稳定性影响的重要结论，为工程中控制不同情况下的旋转射流场后续发展提供了理论依据。     

A novel pre-dilution,swirling jet diffuser to enhance effluent mixing: Hydrodynamics and dilution performance

Diffusers are widely-used to quickly dilute effluents in receiving water bodies. This study proposed a novel diffuser that pre-mixes effluent with ambient water before discharging and that uses the swirling jet to further enhance near-field dilution. The nozzle of the diffuser was examined in two ambient flow conditions: co-flow and counter-flow that are commonly-met in the environment such as oceans due to tidal effect. Physical experiments were first conducted in co-flow on its dilution performance and hydrodynamics, using heated water as the effluent. A 3-D CFD model was developed and calibrated the co-flow scenarios, and then used to investigate the diffuser in counter-flow. The results showed that the nozzle can effectively reduce the maximum temperature rise of the effluent by about 50 % before discharging. The swirling jet from the outlet has a larger shear area, half-width and entrainment rate, enabling the effluent to be rapidly diluted to a minimum of around 10 times at x/D = 6 in co-flow, whereas the dilution for conventional nozzles is about 1 because of the potential core. The flow amplification ratio (α) decreases gradually with increasing velocity ratio in co-flow but increases with increasing velocity ratio in counter-flow. The counter-flow reduces the water drawn into the device; however, the pre-dilution effect at the outlet remains stable. The near-field dilution in counter-flow was significantly enhanced than that in co-flow. Environmental regulations at outfalls and mixing zones can be more easily met using this novel diffuser.     

高水头旋流阻塞复合内消能工水力特性研究

旋流阻塞复合内消能工是适用于高坝泄洪消能的一种新型消能工,为了分析其在超高作用水头下的泄洪消能适用情况,采用模型试验与数值模拟相结合的方法,对200 m作用水头条件下该消能工的水力特性进行了研究。结果表明：泄流量为1 547 m³/s,略大于设计值,满足泄流要求;洞内形成了稳定的空腔旋流,旋流洞段空腔直径约6~7 m,旋流角约60°,壁面压强约110×9.8 kPa,最大点流速约45 m/s;起旋器与旋流洞段为0.050~0.274 Hz的低频脉动,且水流空化数均大于1.2,运行安全;阻塞扩散段末端最小瞬时负压为-3.81×9.8 kPa,且水流空化数较小,但水流掺气率较高,有利于减免发生空蚀;阻塞扩散段末脉动优势频率为46.99 Hz;总消能率达82.1%,消能率高。研究成果可为该复合消能工在高水头下的泄洪消能应用提供参考。     

高坝施工导流洞改为永久竖井泄洪洞水力学研究

本文通过模型试验研究涡室－竖井内消能系统，用内设阻涡坎的涡室连接泄洪洞和竖井，带盲洞的消力并连接竖井和导流洞。探讨了涡室－竖井内消能系统中的流态、边壁时均压力、脉动压力、消能率、消力井尺寸与消能率之间的关系和消能机制等水力学问题。