Waterproofing Technology of Underground Subway Tunnels

The waterproof construction of subway tunnels is a crucial and challenging aspect of subway tunnel engineering.Mastering excellent waterproof construction technology is essential to ensure that the construction meets design requirements and guarantees the safe operation of subway lines.This paper focuses on discussing waterproof construction technology for subway station tunnels.By analyzing the main methods and techniques of underground tunnel construction,as well as the key techniques and difficulties of waterproofing construction,this paper examines the waterproofing construction project of Guangzhou Metro Culture Park Station as a case study.It analyzes the methods,quality management practices,and safety management strategies applied in the project.This paper serves as a reference for tunnel engineering design and construction units in our country,offering insights into effective waterproof construction techniques for subway tunnels.

Preparation and Performance Study of Cementitious Capillary Crystalline Waterproof Materials

Cementitious capillary crystalline waterproof materials(CCCW for short)offer durability and excellent waterproofing properties,making them a popular option for building waterproofing.Some scholars have studied the proportioning of such materials.However,these studies lack the relationship between the impermeability pressure of mortar and the components,and the mechanism of action is somewhat debatable.Therefore,we adopted a two-step method in our experiments.Firstly,we screened out the components that significantly impact impermeability from a variety of active components by orthogonal test.We then optimized the design of the active group ratio using the simplex lattice method.Lastly,we conducted a performance test of the optimal ratio and explored the waterproofing mechanism of homemade CCCW.

Application of New Concept Waterproofing in Xiang'an Undersea Tunnel,China

As a kind of transportation mode for crossing channels, undersea tunnel has incomparable advantages for its directness, convenience, fastness, insusceptibility to weather conditions, and smaller influences on environments. In recent years, with the development of undersea tunnel construction, the design and construction technologies have been greatly enhanced. The first undersea tunnel in China has just been built. Waterproofing is the key technique of undersea tunneling. A new concept of waterproofing scheme of grouting, sealing, draining and divided sections was adopted in the construction of the tunnel based on the researches, the in-situ geological features, the astuteness of the current technology and the cost of construction. The structural details of the sealing and draining system are introduced to illustrate the salient features of the new waterproofing technique. It is hoped that experiences described in the paper can offer guidance for the construction of the extensive undersea tunnels in the coming years.

Synthesizing Self-Crosslinking Waterborne Polyurethane-Silanol Dispersion for Waterproofing Application

Polyurethane dispersions (PUD) have diversified into a myriad of applications over the years. This has led to extensive research on both industrial and laboratory fronts as polyurethane dispersions provide liberty to interplay at the molecular level to diversify the properties of the product which has also led to the development of eco-friendly waterborne dispersions. Yet, waterborne PUDs are limited in their mechanical and physical properties as compared to solvent-based products. The incorporation of crosslinkers in the PUD further bolsters these properties thus improving water and solvent resistance. The incorporation of silanols increases solvent resistance and adhesion of the resultant PUD. In this work, a post crosslinking system based on the ketone-hydrazine mechanism was incorporated into the PUD thus providing the required structural reinforcement for construction application. The targeted application for this work is the use of PUDs for waterproofing.

Study on Preparation of Waterproofing Agent for Mineral Wool Board from Modified C_9 Petroleum Resin

The modified petroleum resin emulsion prepared from the C9petroleum resin was modified with maleic anhydride.The effects of maleic rosin and maleic anhydride addition level,the modification time and the alkali liquor on the properties of the emulsion were discussed.The results showed that the optimum process conditions covered:a maleic anhydride mass fraction of 1.5%,a maleic rosin mass fraction of 10%,a KOH mass fraction of 1%,a petroleum resin modification temperature of 200℃,a petroleum resin modification duration of 3 h,and a modified petroleum resin emulsion/wax emulsion mixing ratio of 1:1.The particle size of modified petroleum resin emulsion prepared under these conditions was equal to 104.166μm.

Elastic Bio-based Polyurethane Nanofibrous Membrane with Robust Waterproof and Breathable Properties

Elastic bio-based waterproof and breathable membranes(EBWBMs) allow the passage of water vapor effectively and resist the penetration of liquid water,making it ideal for use under extreme conditions.In this study,we used a facile strategy to design the bio-based polyurethane(PU) nanofibrous membranes with the nanoscale porous structure to provide the membranes with high waterproof and breathable performances.The optimization of nanofibrous membrane formation was accomplished by controlling the relative ambient humidity to modulate the cooperating effects of charge dissipation and non-solvent-induced phase separation.The obtained EBWBMs showed multiple functional properties,with a hydrostatic pressure of 86.41 kPa and a water vapor transmission(WVT) rate of 10.1 kg·m^(-2)·d^(-1).After 1 000 cycles of stretching at 40% strain,the EBWBMs retained over 59% of the original maximum stress and exhibited an ideal elasticity recovery ratio of 85%.Besides,even after 80% deformation,the EBWBMs still maintained a hydrostatic pressure of 30.65 kPa and a WVT rate of 13.6 kg·m^(-2)·d^(-1),suggesting that bio-based PU nanofibrous membranes could be used for protection under extreme conditions.

Preparation of low-cost waterproofing materials

To address the need for producing a cheap,single-component,hot-applied compound joint sealant with high quality for sealing joints and cracks in concrete and flexible pavements without using primer for installation,a hot-applied modified asphalt sealant was produced by blending up about 30% starch into 20% citric acid.The starch and the asphalt cement were mixed at a temperature of above 160 ℃.Thus the waterproofing asphalt was manufactured to protect the surface of various shapes and types from water leakage using the citric acid.Results indicate that this sealant complies with the requirements of ASTM D-1191,D-6690-06a and D-7116-05.The citric acid is a kind of reliable materials for asphalt cement,which can be widely used in paving and waterproofing construction materials,and this offers profound engineering and economic advantages.

高耐水聚合物水泥防水涂料及其应用性能研究

从JS防水涂料的耐水机理出发,针对性地设计了由聚合物中活性官能团(羧基)与交联剂形成的后交联结构,减弱了水分子对聚合物分子间的增塑作用及对聚合物分子与无机填料界面力的破坏作用,研制了一种具有优异耐水性能的JS防水涂料。该涂料在长期浸水后,仍保持较好的物理力学性能,吸水率<9%、拉伸强度>1.6 MPa,且浸水1年后表观无变化。

盾构隧道管片接缝内外双道密封垫防水性能试验研究

为探究螺栓孔防水对内外双侧布置双道密封垫防水体系的影响,依托某超大直径盾构隧道工程,自主设计新型双道密封垫防水性能测试装置,开展考虑螺栓孔构造的内外双道密封垫防水体系耐水压测试。研究结果表明:1)螺栓孔对内外双侧布置双道密封垫的整体防水性能具有一定的控制作用,当螺栓孔防水能力不足时,其存在将成为内外双道密封垫防水体系的薄弱环节,可能早于内道密封垫发生渗漏,由此降低内外双道密封垫防水性能较单道密封垫的提升水平;2)当螺栓孔防水性能达到要求后,与单道密封垫相比,内外双侧布置双道密封垫防水体系的防水能力大幅提升;3)对于超大直径盾构隧道,当管片接缝采用内外双侧布置双道密封垫时,应确保螺栓孔防水性能满足双道密封垫间的协同防水要求。

上海地铁运营车站出入口底板改造防水技术探讨

上海地铁运营线网中,有为数不少的车站出入口缺少下行自动扶梯,根据相关部门要求,上海地铁已开展了一部分出入口的加装扶梯改造,并计划未来几年覆盖全网;加装扶梯过程中,有部分出入口需要局部开挖结构底板增设扶梯基坑,施工风险较大。以此类涉及出入口改造项目为例,介绍运营车站出入口底板改造中的防水关键技术,以期为今后同类型改造项目的防水设计提供借鉴。

包覆交联法提升玫瑰茄红上染真丝织物色牢度的应用

文章以甲基丙烯酸甲酯、丙烯酸丁酯、2-羟基乙基甲基丙烯酸酯和甲基丙烯酰氧丙基三(三甲基硅氧烷基)硅烷为原料,合成了聚丙烯酸酯类高分子,再将整理后的织物浸于戊二醛溶液中,以达到化学接枝交联的目的,并将其作为纤维包覆材料应用于天然玫瑰茄红色素染色的真丝织物。实验结果表明:整理后真丝织物的色牢度明显提升,湿摩色牢度从2~3级提升到4级,皂洗色牢度从1~2级提到3~4级,并且整理后织物表现出较好的防水效果,水接触角从接近0°提到125°;机械性能显著改善,断裂强度从8.73 MPa提高到26.37 MPa。

深埋岩溶隧道爆破开挖对围岩损伤及渗流特性的影响

深埋岩溶隧道开挖会造成围岩特殊的损伤破坏形式,并且损伤区也会影响围岩渗流场及隧道边界的涌水状况,对深埋岩溶隧道爆破开挖作用下围岩的损伤及渗流特性有重要的研究意义。为了研究爆破开挖对深埋岩溶隧道围岩损伤及渗流的影响规律,基于COMSOL Multiphysics软件建立数值模型并嵌入应力-渗流-损伤耦合方程式进行计算,采用解析法计算了简化条件下岩溶隧道开挖时围岩的应力分布,并与数值计算结果进行比较。结果表明:解析法与数值法计算的围岩应力分布有一致性,爆炸荷载使靠近溶洞侧隧道肩部及脚部区域会产生较大的拉应力;爆破后会在隔水岩柱形成“齿”状损伤区,同时引起肩部及脚部区域流速的增加,其可作为判断溶洞方位的参考依据;溶洞净距减小、洞径及水压增加会引起“齿”延伸倾角及最大涌水位置变化、隧道边界涌水量的增加,可根据“齿”延伸方向判断损伤区检测的合理方位,根据最大涌水位置变化、隧道边界涌水量的变化,合理调整涌水防治措施强度及重点防治部位。研究成果可为溶洞位置判定、隧道损伤区检测以及边界涌水防治措施提供参考。

昌景黄铁路南昌东站抗浮设防水位研究

研究目的:抗浮设防水位是站房基坑工程中一个十分重要的参数,其数值过高会极大增加工程造价,过低又存在工程风险。现行的规范只有原则性的规定,没有也不可能有量化的取值标准。因此,对于有大型基坑的车站工程,进行抗浮设防水位的专项勘察研究,具有重要的工程意义。本文以昌景黄高速铁路南昌东站基坑工程为例,通过现场实测的孔隙水压力、室内外渗透性试验、地下水渗流场模型试验等方法,对抗浮设防水位的确定进行研究。研究结论:(1)抗浮设防水位建议值:使用期可按场坪标高以下0.5 m(即绝对标高20.00 m)取值,施工期按场坪标高(即绝对标高20.50 m)取值,如后期拟建工程的场坪标高有调整,建议使用期按调整后的场坪标高以下0.5 m取值,施工期按调整后的场坪标高取值;(2)工程场地瑶湖、赣抚平原总干渠和抚河等地表水与地下水难以形成水力联系;地下水的承压水与基岩裂隙水存在直接的水力联系,承压水向基岩裂隙中渗流,在基岩裂隙水丰富且具有承压性的区域,基岩裂隙水向上补给承压水;(3)拟建工程场地中,上层滞水和承压水均位于拟建建筑物基底以上,对工程有较大影响,地下水水位的变化对拟建建筑物的抗浮设防设计有重要的影响;(4)上层滞水远期最高水位按工程建设后的地坪标高考虑,承压水远期最高水位标高按19.00 m考虑;(5)本研究成果可为类似工程抗浮设防水位的确定提供借鉴与参考。

格构技术在高铁隧道拱部防水板切割衬砌混凝土缺陷整治中的应用

[目的]许多与高铁隧道衬砌相关的缺陷随着高铁建成年限的增加逐渐凸显,防水板切割衬砌混凝土是其中较为严重的一种缺陷。为了减少结构扰动、降低对线路运行的影响,需采用新技术对高铁隧道拱部防水板切割衬砌缺陷进行整治。[方法]以我国西南地区某设计速度为200 km/h的高铁双线隧道为案例,对其发生拱部防水板切割衬砌混凝土后可采用的2个整治方案(现浇套拱、格构技术)进行了详细分析,并进行了结构的安全性、经济性对比评估。对格构技术缺陷整治方案的施工组织、工艺流程、防护措施及施工效果进行了重点论述。[结果及结论]与其他方案相比,格构技术整治方案充分利用了既有结构的承载能力,仅在局部区域修复隧道,对既有衬砌结构影响较小,对高铁线路的运营影响也较小。该方案能明显降低结构的主应力,减少结构位移,使缺陷衬砌的承载能力满足设计要求。

可水洗隔尿垫吸水防水性检测及结构影响研究

为了开发可水洗隔尿垫产品,研究产品结构对吸水和防水性能的影响,确立了15 mL尿液量为吸水性能测试的关键指标,按压时间10 min为防水性能测试的关键指标,并最终建立了可水洗隔尿垫吸水性和防水性检测方法。使用该方法对市售的可水洗隔尿垫产品进行检测和评价,结果表明:可水洗隔尿垫产品应至少包含吸水层和防水层,且吸水层在防水层之上,以保证较好的吸水性;以针织物为面层的隔尿垫产品具有更好的柔软性和舒适性;建议隔尿垫产品进行压合或绗缝,否则填充物易鼓包,影响吸水效果;防水膜或防水层均可以达到期望的防水效果。

页岩储层防水锁聚合物水基钻井液体系研究

开发一种适用于页岩储层的水基钻井液体系,以优化钻井过程中的页岩稳定性和防水锁效果。通过页岩滚动回收率、线性膨胀率测试以评价不同处理剂的效果。结果表明:0.5%WEDM+1.5%SFTH复配体系可显著提高页岩的回收率,同时最大线性膨胀率由37.6%降至16.80%。封堵剂CMS在控制滤失量方面表现出色,包被剂KPAM在提高钻井液稳定性和降低滤失量方面具有显著效果。防水锁水基钻井液配方为:4%基浆+1.0%WEDM+1.5%SFTH+1.5%CMS+0.3%KPAM+2.0%op-10。该体系在高温高压条件下展现出了优异的流变特性和滤失控制能力,特别是在抗温性和抗污染性方面表现卓越。该体系在150℃高温下保持了良好的稳定性,且对NaCl和CaCl_(2)的抗污染能力强。在储层保护方面,该体系能有效减少钻井液对储层的伤害,实现高达85.69%的渗透率恢复率,同时形成的泥饼质量良好。研究成果对于页岩气开采具有重要意义。

基于突变理论的隔水岩体失稳分析及安全厚度计算

为了保障岩溶突水隧道施工和运营安全,基于弹性梁模型,应用突变理论建立岩溶突水顶板在动力扰动下失稳的双尖点突变模型;综合考虑围岩性质、静水压力、动力扰动等因素,分析岩溶突水隧道顶板的失稳机制和破坏条件,建立其失稳突变的判别方程,并采用Matlab软件编程,求解顶板的最小安全厚度;同时,为了避免当静水压力过大时,突变理论公式的不合理性,单独计算仅在静水压力的情况下的最小安全厚度,并取两者计算值中的更大值。结果表明:隔水岩体是否保持稳定是由岩体内外因素共同决定的;岩体跨度越长,岩体最小安全厚度越大;岩体弹性模量越大,岩体最小安全厚度越小。在振动频率一定时,爆破荷载越大,岩体最小安全厚度越大;在爆破荷载的大小一定时,爆破振动的频率越大,岩体最小安全厚度越小;静水压力越大,岩体最小安全厚度越大。该岩溶突水隧道顶板安全厚度计算方法具有可行性与较高的准确性。

河流下综放工作面覆岩破坏特征和陷落柱防水煤柱留设研究

目的长平矿Ⅲ2317工作面在开切巷处揭露陷落柱,地表丹河流向与工作面推进方向一致,受采动影响,陷落柱内部水体及河水可能通过开采裂隙导入回采空间,从而造成工作面突水。针对以上问题,方法本文采用理论分析、数值模拟和现场观测等方法,对回采工作面覆岩“两带”高度、覆岩破坏特征和陷落柱煤柱留设宽度进行研究。结果结果表明:工作面顶板垮落带与导水裂隙带最大发育高度分别为18.38,93.85 m,河水对工作面不构成突水威胁;无煤柱开采时,陷落柱一侧顶板裂隙沿陷落柱胶结面向上高度发育;结合理论计算和数值模拟分析,确定煤柱宽度为35 m。工作面在留设35 m煤柱条件下安全完成回采,地表变形特征符合预期,最大下沉量达到4000 mm,回采过程中工作面未发生突水事故。结论研究结果可为类似条件下的煤层安全开采提供理论和经验支撑。

富水砂卵石地层盆形冻结止水技术研究

为解决全断面砂卵石地层地下工程的地下水控制问题,提出盆形冻结止水技术。首先,采用三轴力学试验研究冻结砂卵石的压缩力学特性和蠕变力学特性;然后,采用大尺度物理模型试验和数值模拟方法研究盆形冻结的温度场扩展规律,并根据研究结果进一步提出盆形冻结积极冻结期的群孔布置技术和维护冻结期的精细化控制技术。结果表明:1)低围压(小于3 MPa)条件下,三轴抗压强度与围压呈正线性相关,然后围压继续增大时,强度基本不变;基于损伤理论建立冻结砂卵石全过程蠕变模型。2)荷载对冻胀率及融沉系数影响最大,细粒土质量分数次之,原状饱和砂卵石是不冻胀材料,并由此建立饱和砂卵石冻胀率及融沉系数三维预测模型。3)基于大型物理模型试验及数值模拟结果,盆形冻结可以在地下水渗流条件下形成完整的盆形结构,起到有效止水的效果。4)盆底冻结管在冻结过程中表现出与单管冻结迥异的“群孔效应”,根据试验结果提出包含冻结管间距、土体导热系数、渗流速度3因素的积极冻结期冻结管合理间距的确定与布置技术。5)为节约维护冻结期的能源,提出隔排切割冻结管、仅保留盆壁冻结管2种维护形式以对冻结区域进行精细化控制,经过分析,2种方式均可以有效满足盆形结构维护期的冷量供给,保持完整的盆形形态。

硅溶胶-异丁基三乙氧基硅烷复合乳液对泡沫混凝土防水性能的影响

[目的]研究硅溶胶-异丁基三乙氧基硅烷(IBTS)复合乳液对泡沫混凝土防水性能的影响,为拓宽其应用提供实验数据。[方法]通过宏观力学特性试验和微观结构分析,综合考察了该复合乳液对泡沫混凝土的防护效果。[结果]涂抹了复合乳液的泡沫混凝土表现出比涂抹了单一IBTS乳液的泡沫混凝土更优异的抗渗透性能和耐久性,其水渗透深度和碳化深度更小,浸水48 h后的吸水率为0.46%,氯离子迁移系数为1.1×10^(-12)m^(2)/s,冻融240次后的质量损失率为0.55%,且动弹性模量仍维持冻融试验前的85.34%。[结论]复合乳液的防水机理涉及表面效应、化学反应、物理效应等多个方面,通过形成致密的防水层、填充孔隙和微裂纹、吸附并包固水分子等方式来防止水分渗透和扩散,从而提高泡沫混凝土的防水性能。