透水模板结合真空脱水工艺在船闸混凝土中的应用

针对船闸混凝土工程,以室内试验研究和现场工程应用相结合的方法,探讨透水模板结合真空脱水工艺对混凝土外观质量、表层强度、抗冲磨性能和抗渗性能的影响.结果表明,在不改变混凝土配合比的前提下,透水模板衬垫结合真空脱水工艺可有效降低混凝土表层水胶比,提高混凝土密实性,改善混凝土外观质量;同时提高混凝土抗冲磨性能和混凝土抗渗性能.

基于温度场及应力场仿真分析的船闸混凝土配合比设计

针对施桥三线船闸工程中船闸钢筋混凝土结构设计,基于混凝土抗裂性能优化,采用ANSYS分析软件对廊道和闸室不同混凝土配合比进行仿真分析,通过比较廊道和闸室混凝土温度场、温度应力分布及其随时间变化的规律,提出较优的混凝土配合比。

岩质高边坡与船闸混凝土结构相互作用分析

在船闸建造工程中的高边坡岩体开挖之后由于其中的地应力可能没有完全释放,其产生的变形会推挤船闸混凝土结构,对船闸混凝土结构的稳定性产生不利影响,从而导致工程的质量、施工安全性大幅下降。因此,有必要分析各种应力释放比例条件下船闸结构应力和位移的分布情况,核算断面强度并计算地基反力及沉降。本文以贵州某高水头船闸为例,运用数值模拟软件ABAQUS,对三种应力释放的情况下的超高边坡及船闸混凝土结构进行模拟,最后对模拟结果进行分析,为设计工作提供依据。

粉煤灰掺量对船闸混凝土关键工程性能的综合影响

为研究粉煤灰掺量对强度较低的C25船闸混凝土的性能影响规律,针对不同粉煤灰掺量混凝土的工作性能、力学性能、体积稳定性和热学性能展开研究与分析。试验结果与分析表明,在8%~15%范围内,提高C25混凝土中粉煤灰掺量可以有效提升混凝土各项性能以及耐久性,对大体积船闸混凝土的抗裂和抗冲磨耐久性能有积极作用;在大于15%的范围,提高混凝土中粉煤灰掺量对强度较低的C25混凝土各项性能提升不明显。

船闸工程混凝土质量通病的防治

结合船闸工程特点,探讨了船闸工程混凝土常见质量通病发生的部位、原因,并根据结构特点介绍了船闸混凝土常见质量通病的预防补救措施。

船闸闸室混凝土岸墙裂缝成因分析和预防措施

结合混凝土船闸岸墙发生裂缝的实例,分析影响混凝土船闸岸墙发生裂缝的主要因素:一是工程设计不合理,二是施工工艺存在缺陷,三是受到温度应力影响,四是工程运行条件较差,五是养护措施不得当。综上,提出了发生裂缝的具体措施。

Construction monitoring of lock head base plate using distributed optical fibre sensing technique

The concrete hydration heat release process of the base plate is monitored using Roman optical time domain reflectometry（ROTDR） sensing sensors. The monitoring data shows that the internal maximum temperature of the base plate is about 54 ℃ after the concrete was cured for 120 h. The fiber Bragg grating （FBG） temperature sensors are adopted to measure the surface temperature of the concrete and the temperature results are used to compensate the data measured by the pulse-prepump Brillouin optical time-domain analyzer （PPP-BOTDA） to obtain the real concrete surface strain of the base plate. The monitoring data is analyzed to obtain a clear understanding of the strain state of the base plate under the effect of concrete hydration heat release. The monitoring results demonstrate the potential of distributed optical fibre sensing techniques as a powerful tool in real-time construction monitoring, and also provide an important insight into the design, construction and maintenance of large hydraulic structures.

Finite element analysis on nut post structure of Three Gorges Project ship lift

A nonlinear finite element model of the nut post reinforced concrete （RC） structure of the safety mechanism in the Three Gorges Project （TGP） ship lift was built by ANSYS software. Some irregular structures such as the nut post and the rotary rod were divided by curved surface into a series of regular parts, and the structures were all meshed to hexahedron. Constraint equations were defined between two interfaces with different element sizes and mesh patterns. PRETS179 elements were used to simulate the preload in the tendons and the pre-stressed screws, and the loss of prestressing force was calculated. Five extreme load cases were analyzed. The stress of each part in the structure was obtained. The results indicate that the maximum compressive stress of concrete C35 is 24.13 MPa, so the concrete may be partially crushed; the maximum tensile stress of the grouting motar is 6.73 MPa, so the grouting motar may partially fracture; the maximum yon Mises stress of the rotary rod is 648.70 MPa, therefore the rotary rod may partially yield.

船闸闸室墙体混凝土裂缝的成因分析及处理措施

裂缝是大体积混凝土施工中常见的技术难题,也是工程质量控制的重要内容,本文以马山埠船闸工程闸室侧墙施工后局部出现裂缝为例,对钢筋混凝土侧墙产生裂缝的原因进行归纳分析,提出了预防和处理措施。