Construction Technology of Deep Foundation Pit Support in Municipal Civil Engineering Foundation Construction

Municipal civil engineering is the key content of municipal construction,and the construction scale is usually large.The quality of the project plays an important role in the development of urban economy.Due to the rapid increase of high-rise buildings,skyscrapers and underground buildings,the construction technology of deep foundation pit support has gradually become an indispensable construction technology.Therefore,the selection of foundation pit support construction technology is crucial in ensuring that whether the foundation is firm and stable,and whether the subsequent construction activities can be carried out smoothly.In view of this,the article discusses the application of deep foundation pit support construction technology in municipal civil engineering,aiming to provide reference for subsequent projects.

Analysis on Construction Technology of Concrete Structure in Civil Engineering

The rapid development of science and technology puts forward higher requirements for new building construction,especially in civil engineering construction.The construction quality of construction engineering is the core management and the testing link.The Concrete structure is an important safety and quality guarantee in the project and is the top priority in the civil engineering.In civil engineering,the concrete structure has an important social impact on the continuous research and development,and application of construction technology.This paper,discuss the advantage and disadvantage of using concrete in building construction.

Construction Technology and Safety Risk Control Measures of Deep Foundation Pit Excavation

Deep foundation pit excavation is a basic and key step involved in modern building construction.In order to ensure the construction quality and safety of deep foundation pits,this paper takes a project as an example to analyze deep foundation pit excavation technology,including the nature of this construction project,the main technical measures in the construction of deep foundation pit,and the analysis of the safety risk prevention and control measures.The purpose of this analysis is to provide scientific reference for the construction quality and safety of deep foundation pits.

Earthwork and the Strategies of Concrete Construction Technology Application in Building Construction

The pouring of mass concrete and earthwork account for a large proportion in building construction,which can play a decisive role in the quality of the building.Therefore,it is necessary to understand the technology of earthwork and concrete engineering in the process of building construction and propose reasonable application strategies.

Application of Deep Foundation Pit Construction Technology in Civil Engineering Construction

As one of the commonly used technologies in modern civil engineering,the construction technology is becoming more and more widely used with the continuous growth of building height.In the construction process of highrise buildings,the deep foundation pit support provides the necessary stability for the foundation structure of the building project,and more effectively guarantees the quality of the project.Through the reasonable supporting structure,the deep foundation pit technology can effectively prevent the risk of soil collapse,foundation pit deformation and other risks,and improve the safety factor of the whole construction project.Especially in the high-rise buildings,the deep foundation pit support technology can consolidate the foundation for the long-term stability of the project,and significantly prolong the service life of the building.The continuous development of deep foundation pit construction technology is the inevitable demand of high-rise building construction,and also provides a powerful help for the development of civil engineering industry.Based on this,this paper focuses on the application of deep foundation pit construction technology in civil engineering construction.

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.

Study on Durability of Recycled Aggregate Concrete in High-Temperature and Complex Environments

Recycled aggregate concrete refers to a new type of concrete material made by processing waste concrete materials through grading,crushing,and cleaning,and then mixing them with cement,water,and other materials in a certain gradation or proportion.This type of concrete is highly suitable for modern construction waste disposal and reuse and has been widely used in various construction projects.It can also be used as an environmentally friendly permeable brick material to promote the development of modern green buildings.However,practical applications have found that compared to ordinary concrete,the durability of this type of concrete is more susceptible to high-temperature and complex environments.Based on this,this paper conducts theoretical research on its durability in high-temperature and complex environments,including the current research status,existing problems,and application prospects of recycled aggregate concrete’s durability in such environments.It is hoped that this analysis can provide some reference for studying the influence of high-temperature and complex environments on recycled aggregate concrete and its subsequent application strategies.

Influence of Collapsible Loess on Foundation and its Treatment Strategy

The properties of collapsible loess are complex.The self-gravity of overlying soil,sei gravity stress and additional stress act together,which will damage the soil structure and lead to the deformation of the soil structure.Collapsible loess is widely distributed in Northwest and Northeast China.A series of problems caused by its structural characteristics will affect the quality of foundation construction.Therefore,construction enterprises need to deeply study the foundation treatment measures of collapsible loess,so as to avoid the uneven settlement after the construction of collapsible yellow soil foundation.This paper analyzes from the judgment and classification of collapsible loess,studies the impact of collapsible loess on building fbxmdation construction,and explores the specific construction treatment measures of collapsible loess,in order to promote the effective application of foundation construction.

Wireless remote spatiotemporal monitoring of high-fill foundation deformation

The spatial and temporal deformation patterns and deformation control indicators of highfill foundations directly affect the design,construction and operational safety of high-fill projects.In situ monitoring can comprehensively reflect the deformation of high-fill during and after construction.In this paper,we have first designed and installed an integrated wireless remote monitoring system for high-fill to achieve real-time dynamic monitoring of settlement,pore water pressure and soil pressure of the fill foundation.Based on the monitoring results of nearly one year of the construction period and two years after construction,it was found that the deformation amount and deformation rate of the high-fill foundation showed a non-linear growth relationship with the filling rate and filling height.The settlement deformation of the high-fill foundation during the loading period was mainly dominated by the original foundation soil,accounting for 54.4%of the total settlement on average;the settlement deformation during the post-construction period was mainly dominated by the filling body,accounting for 77.04%of the total settlement on average,and the settlement deformation during the post-construction period mainly occurred in the first year after construction.The analysis of the deformation mechanism suggests that the deformation of the filling body is dominated by exhaust consolidation during the loading period and drainage consolidation during the post-construction period;the deformation of the original foundation soil is dominated by drainage consolidation during the loading period and drainage consolidation develops slowly during the post-construction period.It is recommended that the original foundation should be reinforced before the large area filling construction,and that the filling rate should be strictly controlled during construction.The research results can provide a scientific basis for deformation calculation and stability assessment of high-fill foundations.

Analysis of Concrete Crack Treatment Technologies in Buildings

With the continuous development of civil engineering,concrete crack treatment technology has become an important research field.This paper proposes treatment techniques for different types of cracks,including the prevention and repair of surface cracks,the reinforcement and grouting of structural cracks,and the design and construction of controlled cracks through the analysis of the causes and classification of concrete cracks.The methods and suggestions proposed in this paper are practical and can improve the quality and safety of buildings.

Compressive strength prediction of sprayed concrete lining in tunnel engineering using hybrid machine learning techniques

Sprayed concrete lining is a commonly employed support measure in tunnel engineering,which plays an important role in construction safety.Compressive strength is a key performance indicator of sprayed concrete lining,and the traditional measuring method is time-consuming and laborious.This paper proposes various hybrid machine learning algorithms to accomplish the advanced prediction of compressive strength of sprayed concrete lining based on the mixture design.Two hundred and five sets of experimental data were collected from a water conveyance tunnel in northwestern China for model construction,and each set of data was made up of six basic input variables(i.e.,water,cement,mineral powder,superplasticizer,coarse aggregate,and fine aggregate)and one output variable(i.e.,compressive strength).In order to eliminate the correlation between input variables,a new composite indicator(i.e.,the water-binder ratio)was introduced to achieve dimensionality reduction.After that,four hybrid models in total were built,namely BPNN-QPSO,SVR-QPSO,ELM-QPSO,and RF-QPSO,where the hyper-parameters of BPNN,SVR,ELM,and RF were auto-tuned by QPSO.Engineering application results indicated that RF-QPSO achieved the lowest mean absolute percentage error(MAPE)of 3.47% and root mean square error(RMSE)of 1.30 and the highest determination coefficient(R^(2))of 0.93 in the four hybrid models.Moreover,RFQPSO had the shortest running time of 0.15 s,followed by SVR-QPSO(0.18 s),ELM-QPSO(1.19 s),and BPNN-QPSO(1.58 s).Compared with BPNN-QPSO,SVR-QPSO,and ELM-QPSO,RF-QPSO performed the most superior performance in terms of both prediction accuracy and running speed.Finally,the importance of input variables on the model performance was quantitatively evaluated,further enhancing the interpretability of RF-QPSO.

人工海岛建设技术现状与同步建造新思路

随着城市发展、海洋资源开发以及旅游业需求的不断增长,人类开展了人工海岛的建设工作.然而,传统的非围堰式填海和围堰式湿法填海方法存在显著不足:地基处理缺乏系统性的加固措施,容易导致较大沉降;回填材料施工过程中易对海洋环境造成扰动,影响水质和生态系统;后续工程施工中存在重复开挖工序,增加了工程量和成本.为了解决上述不足,提出一种同步建造人工海岛城市的施工方法,即围堰式干法填海.该方法的具体操作是:在预定区域的外侧两端相向构筑围堰,同时对填土区进行海上水泥土搅拌桩地基加固;围堰施工完成后,抽取海水并在原状海底平整铺设垫层;进行建筑桩基础施工,开展底部标高处的隧道、管廊和地下室等装配式地下结构的施工,并同步进行土体分层回填;回填至上一层结构的施工工作面,完成结构施工后再次回填,如此循环,直至回填至指定标高.同步建造人工海岛的方法能够减少填筑材料的用量以及再开挖施工的费用,极大地缩短建设周期、降低建设成本,并且减轻填海过程对海洋环境造成的污染.研究成果可为大型人工海岛的建造提供新的思路和参考依据.

水电工程天然建筑材料勘察评价要点与利用

天然建筑材料勘察评价是水电工程地质勘察工作的重要内容,关系到坝型选择、施工进度与大坝运行安全。近年水电工程建设中常遇到防渗土料、堆石料、混凝土骨料等天然建筑材料质量无法满足设计要求,但经采取针对性料源改性或工程处理方案后,可满足筑坝材料需求的工程案例。结合多座大型水电工程建设经验,总结土料、石料勘察评价工作要点,探讨相应料源改性或工程处理思路,并提出天然建筑材料选择中的几个关注点。

顶管诱发条形基础沉降特征分析

顶管开挖将引起地表扰动,影响地面构筑物的安全。为了研究顶管施工对条形基础沉降的影响,依托合肥市顶管涵洞下穿既有建筑工程,采用有限元软件仿真计算顶管下穿过程,研究施工过程中条形基础的沉降特征,分析土仓压力、注浆压力、顶管直径和埋深对条形基础沉降的影响规律。研究表明,土仓压力增大会减小基础中心的沉降;注浆压力提高会使基础的初始隆起和其后沉降加剧;管径增加会减少基础边缘的沉降,当管径为3 m时基础中心沉降最大,为5.59 mm;随着埋深的增加,土仓压力和注浆压力对基础的影响减弱,但顶管沿轴向扰动范围扩大,5 m埋深时沉降量最大,为5.49 mm;顶管施工时,应考虑建筑基础在顶进扰动过程中的局部倾斜值是否满足要求,建议使用较小注浆压力和较大埋深,并选用合适管径。

综合交通枢纽工程盖挖逆作法研究与应用

基于北京城市副中心站综合交通枢纽工程的特殊地理位置和地质条件,本项目采用盖挖逆作法进行地下建筑的施工。首先对地下结构工程的施工方法进行了概述,基于项目实际工程情况对盖挖逆作的施工重难点进行分析,确定了合理高效的盖挖逆作施工顺序;其次对盖挖逆作工程中的土方开挖技术、基坑降水施工技术、基坑监测技术等进行创新改进,提高了工程效率的同时保证了安全度。此外,针对盖挖逆作塔式起重机基础施工技术进行改进,采用钢管桩式混凝土承台塔式起重机基础。最后,在盖挖逆作技术基础上结合BIM和AR技术进行了创新应用,推动了盖挖逆作工程的现代化发展。

水利工程施工中软土地基处理技术

地基是水利工程的基础,地基施工质量直接影响到了水利工程整体质量,因此,提高地基施工质量至关重要。软土地基是水利工程地基常见的一种类型,这种类型的地基具有高压缩性、抗剪强度低、易破坏、透水性差等特点,如果地基处理不当,就容易出现沉降、断裂、倾斜等问题,进而影响到水利工程质量。因此,在水利工程软土地基施工中,施工企业要严格按照科学的技术进行,确保施工质量过关。

近接基坑工程有限土体失稳模式研究

随着城市地铁建设不断发展,基坑紧邻既有地下结构的情况日益增多,然而仍然缺乏对近接基坑工程土体失稳模式的系统研究。针对既有地铁车站近接增建基坑工程,采用数值分析方法研究近接基坑工程对称/非对称有限土体失稳模式,提出不同失稳模式下适用条件,分析内支撑数量、基坑深度、基坑与既有地铁车站空间位置关系等对土体稳定性及滑移面性状的影响规律。研究表明:(1)近接基坑工程非对称和对称有限土体失稳模式分别有3种和6种情况;(2)随着内支撑数量的增加,滑移体范围不断扩大,且起始位置沿围护结构不断下移,有限土体稳定性安全系数逐渐增加;(3)随着基坑深度的增加,滑移体的范围先增大后减小,有限土体稳定性安全系数逐渐减小;(4)针对近接基坑工程非对称滑移面分析,随着既有地铁车站覆土厚度的增加,滑移面在既有地铁车站侧的近接范围逐渐减少且起始位置外移。以上研究可以为既有地铁车站近接增建基坑工程的有限土体土压力的计算、基坑围护结构的设计以及既有地铁车站安全控制措施的选取提供理论依据。

建筑工程中混凝土施工质量控制策略研究

建筑工程的质量不仅关系着人们的人身健康和安全,也直接影响着人们的财产安全,随着社会经济的发展,全国各地的房产建筑工程如雨后春笋般迅猛崛起。随着人们对生活品质的追求,对建筑工程的质量要求也越来越高。在现代建筑工程当中,钢筋混凝土施工工艺已经成为一种常见的施工技术,虽然混凝土施工技术已经越来越成熟,但还存在较多的质量问题和缺陷。基于此,本文围绕建筑工程中混凝土施工的相关问题展开了讨论,并提出一些科学有效的质量控制策略。

混凝土结构防渗漏施工技术在房屋建筑工程中的应用

在房屋建筑工程中,混凝土结构防渗漏施工技术的应用至关重要,直接影响建筑的整体质量和居住体验。合理应用混凝土结构防渗漏施工技术,能有效解决房屋建筑渗漏问题,提升建筑质量,保障居民安全。基于此,文章首先探讨了研究了房屋建筑容易出现渗漏问题的几个结构部位,然后研究了防渗漏施工技术在房屋建筑工程中的应用以及施工要点,以期能有效预防结构渗漏病害问题的发生。

钢筋混凝土模板施工技术在建筑工程中的应用

为进一步提高建筑工程施工质量,文章结合实际工程,对钢筋混凝土模板施工技术展开了研究。结果显示,在施工前期,做好模板材料选型、承载力与稳定性计算,明确具体的浇筑要求,并严格把控施工过程技术要点,能够持续推动建筑行业的健康发展。