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DX桩 15

承载力 7

沉降 7

人工流产 2

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同步注浆 2

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数值分析 2

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Experimental study on pile-end post-grouting piles for super-large bridge pile foundations

Weiming GONG, Guoliang DAI, Haowen ZHANG

《结构与土木工程前沿(英文)》 2009年 第3卷 第2期   页码 228-233 doi: 10.1007/s11709-009-0019-0

摘要: The application of pile-end post-grouting piles for super-large bridge pile foundations in some important projects was introduced in this paper. There are totally 21 test piles. The maximum pile diameter varies from 2.5 m to 3 m, and the maximum length is 125 m; the bearing capacity of the post-grouting piles is over ten thousands tons. Based on the test results, the bearing capacity, displacement, and bearing characteristic before and after grouting were analyzed. The results show that the bearing capacity of the piles are increased in different degrees after grouting although the technical parameters, including the patterns of grouting pipes, pressure, dosages of cement, duration of grouting lasting time, are different. However, the obtained values are very discrete. In addition, the calculation formula for the post-grouting piles under specified grouting condition was deduced based on the statistics analysis results of 57 test piles. The research results have been applied in the design of bridge foundation.

关键词: self-balanced testing technique     pile-end post-grouting     bearing capacity     grouting technology    

DX桩与后压浆钻孔灌注桩现场试验研究

刘春刚,柴小兵,欧阳义,贺德新

《中国工程科学》 2012年 第14卷 第1期   页码 80-85

摘要:

对DX桩进行了现场竖向抗压静载试验,并与后压浆直孔灌注桩进行了比较。结果表明,DX桩和后压浆钻孔灌注桩都可以提高桩的承载力和控制桩的沉降,4根试验桩的试验效果相差不大,但DX桩能以桩径小、桩长短满足大承载力的桩基,达到极限承载力时,混凝土的单方承载力是后压浆钻孔灌注桩的1.5倍,可以减少工程材料,降低工程造价;且DX桩施工工艺更简单,能加快施工进度。

关键词: DX桩     静载荷试验     承载力     沉降    

大跨径悬索桥钢塔塔底钢混连接处承压板后压浆施工技术

张平,蒋建,董勤军,蔡伟,刘颖

《中国工程科学》 2010年 第12卷 第4期   页码 53-57

摘要:

泰州大桥为三塔两跨悬索桥,中塔纵桥向为人字型钢塔,两条斜腿在塔座顶面用螺杆锚固,通过钢塔D0段承压板与塔座顶面传递压力。塔座顶面混凝土具有双向斜坡度,在塔座顶面预留压浆空隙,待钢塔D0段安装定位后,再对预留空隙采用压浆机压入无收缩高强度水泥浆作为承压板的支承面。文章简要介绍了D0段承压板压浆施工技术及施工工艺。

关键词: 高强度     自流平     无收缩     后压浆     工艺    

Upgrading pyrolytic carbon-blacks (CBp) from end-of-life tires: Characteristics and modification methodologies

Jiaxue Yu, Junqing Xu, Zhenchen Li, Wenzhi He, Juwen Huang, Junshi Xu, Guangming Li

《环境科学与工程前沿(英文)》 2020年 第14卷 第2期 doi: 10.1007/s11783-019-1198-0

摘要: Modification methodologies of upgrading CBp from ELTs were reviewed. Surface microstructures and physiochemical properties of CBp were analyzed. Future perspectives of ELTs pyrolysis industries were suggested. Over 1 billion end-of-life tires (ELTs) are generating annually, and 4 billion ELTs are currently abandoned in landfills and stockpiles worldwide, according to the statistics, leading to the environmental and health risks. To circumvent these issues, pyrolysis, as an attractive thermochemical process, has been addressed to tackle the ELTs’ problem to reduce the risks as well as increase the material recycling. However, due to the lack of systematic characteristic analysis and modification methods, poor quality of CBp limits the improvement of ELTs pyrolysis in industry applications, which plays a crucial role in the economic feasibility of pyrolysis process. In this review, we have summarized the state-of-the-art characteristics and modification methodologies of the upgrading of CBp, to in-depth understand the surface microstructures and physiochemical properties of CBp for the foundation for modification afterwards. By virtue of the proper selection of modification methods and modifying agents, the new generation of multifunctional carbon materials with desired properties can be instead of the traditional materials of CB, promising broader and various application fields.

关键词: Pyrolysis carbon-blacks     CBp     Post-pyrolysis     Demineralization     Surface modification    

Topology-independent end-to-end learning model for improving the voltage profile in microgrids-integrated

《能源前沿(英文)》 2023年 第17卷 第2期   页码 211-227 doi: 10.1007/s11708-022-0847-3

摘要: With multiple microgrids (MGs) integrated into power distribution networks in a distributed manner, the penetration of renewable energy like photovoltaic (PV) power generation surges. However, the operation of power distribution networks is challenged by the issues of multiple power flow directions and voltage security. Accordingly, an efficient voltage control strategy is needed to ensure voltage security against ever-changing operating conditions, especially when the network topology information is absent or inaccurate. In this paper, we propose a novel data-driven voltage profile improvement model, denoted as system-wide composite adaptive network (SCAN), which depends on operational data instead of network topology details in the context of power distribution networks integrated with multiple MGs. Unlike existing studies that realize topology identification and decision-making optimization in sequence, the proposed end-to-end model determines the optimal voltage control decisions in one shot. More specifically, the proposed model consists of four modules, Pre-training Network and modified interior point methods with adversarial networks (Modified IPMAN) as core modules, and discriminator generative adversarial network (Dis-GAN) and Volt convolutional neural network (Volt-CNN) as ancillary modules. In particular, the generator in SCAN is trained by the core modules in sequence so as to form an end-to-end mode from data to decision. Numerical experiments based on IEEE 33-bus and 123-bus systems have validated the effectiveness and efficiency of the proposed method.

关键词: end-to-end learning     microgrids     voltage profile improvement     generative adversarial network    

Seismic performance of fabricated continuous girder bridge with grouting sleeve-prestressed tendon composite

《结构与土木工程前沿(英文)》   页码 827-854 doi: 10.1007/s11709-023-0954-1

摘要: The seismic performance of a fully fabricated bridge is a key factor limiting its application. In this study, a fiber element model of a fabricated concrete pier with grouting sleeve-prestressed tendon composite connections was built and verified. A numerical analysis of three types of continuous girder bridges was conducted with different piers: a cast-in-place reinforced concrete pier, a grouting sleeve-fabricated pier, and a grouting sleeve-prestressed tendon composite fabricated pier. Furthermore, the seismic performance of the composite fabricated pier was investigated. The results show that the OpenSees fiber element model can successfully simulate the hysteresis behavior and failure mode of the grouted sleeve-fabricated pier. Under traditional non-near-fault ground motions, the pier top displacements of the grouting sleeve-fabricated pier and the composite fabricated pier were less than those of the cast-in-place reinforced concrete pier. The composite fabricated pier had a good self-centering capability. In addition, the plastic hinge zones of the grouting sleeve-fabricated pier and the composite fabricated pier shifted to the joint seam and upper edge of the grouting sleeve, respectively. The composite fabricated pier with optimal design parameters has good seismic performance and can be applied in high-intensity seismic areas; however, the influence of pile-soil interaction on its seismic performance should not be ignored.

关键词: seismic performance     continuous girder bridge     grouting sleeve-prestressed tendon composite connections     grouted sleeve connection     design parameters    

Finite element prediction on the response of non-uniformly arranged pile groups considering progressivefailure of pile-soil system

Qian-Qing ZHANG, Shan-Wei LIU, Ruo-Feng FENG, Jian-Gu QIAN, Chun-Yu CUI

《结构与土木工程前沿(英文)》 2020年 第14卷 第4期   页码 961-982 doi: 10.1007/s11709-020-0632-5

摘要: A uniform arrangement of individual piles is commonly adopted in the conventional pile group foundation, and basin-shaped settlement is often observed in practice. Large differential settlement of pile groups will decrease the use-safety requirements of building, even cause the whole-building tilt or collapse. To reduce differential settlement among individual piles, non-uniformly arranged pile groups can be adopted. This paper presents a finite element analysis on the response of pile groups with different layouts of individual piles in pile groups. Using the user-defined subroutine FRIC as the secondary development platform, a softening model of skin friction and a hyperbolic model of end resistance are introduced into the contact pair calculation of ABAQUS software. As to the response analysis of a single pile, the reliability of the proposed secondary development method of ABAQUS software is verified using an iterative computer program. The reinforcing effects of individual piles is then analyzed using the present finite element analysis. Furthermore, the response of non-uniformly arranged pile groups, e.g., individual piles with variable length and individual piles with variable diameter, is analyzed using the proposed numerical analysis method. Some suggestions on the layout of individual piles are proposed to reduce differential settlement and make full use of the bearing capacity of individual piles in pile groups for practical purposes.

关键词: numerical simulation     non-uniformly arranged pile groups     differential settlement     pile-soil interaction    

Efficacy and safety of JAK inhibitor INC424 in patients with primary and post-polycythemia vera or post-essential

null

《医学前沿(英文)》 2016年 第10卷 第4期   页码 437-443 doi: 10.1007/s11684-016-0472-9

摘要:

A phase II study (A2202) was performed to evaluate the efficacy and safety of JAK inhibitor ruxolitinib in 63 Chinese MF patients. Ruxolitinib was given twice a day (bid) at a starting dose of 15 mg (n=25) or 20 mg (n=38) based on a baseline platelet count. About 94.7% of the patients achieved a reduction in spleen size, 27.0% of which exhibited significant reduction (≥35%) at week 24. Significant improvement in debilitating constitutional symptoms, as assessed by MFSAF v2.0, was observed in patients treated with ruxolitinib. Ruxolitinib treatment was generally well tolerated by Chinese patients. Although the treatment was associated with an increase in certain adverse events (AEs) that were established as identified risks (anemia and thrombocytopenia), these AEs were considered manageable in this clinical setting. Ruxolitinib provided substantial reductions in splenomegaly and improvements in symptoms, and was well-tolerated by Chinese patients with MF.

关键词: JAK     ruxolitinib     Chinese patients     myelofibrosis    

高压富水断层“外堵内固注浆法”设计新理念与工程实践

张民庆,张梅

《中国工程科学》 2009年 第11卷 第12期   页码 26-34

摘要:

宜万铁路齐岳山隧道F11断层由断层角砾岩、破裂岩、断层泥组成,断层内富含高压水,超前探孔单孔最大涌水量1 800 m3/h,水压力2.5 MPa。针对F11高压富水断层,前期按“以堵为主、限量排放”施工原则,采取全断面帷幕注浆措施,注浆工程量大、进度慢。为及早攻克F11高压富水断层,建设单位多次邀请院士、专家现场踏勘、研讨,提出“注浆加固、分水降压、快挖快封、加强监测、综合治理”施工技术方案,将全断面帷幕注浆调整为外堵内固注浆。对于高压富水断层,通常的设计是加固圈厚一些、加固体强一些,而外堵内固注浆是将隧道周边岩体、水量及水压力分布假定为不均匀性,从而通过超前探孔锁定弱水区和强水区,针对弱水区采取基本注浆,对强水区采取加强注浆,注浆机理为“封堵裂隙、减少水量;固结围岩、改良地层。”注浆时,先通过区域定位孔进行无约束注浆堵水,从而使地层中水量得到有效控制,然后按“合理步距、封堵水流,由外到内、环环相扣,间隔跳孔、锁定水源,增加补孔、区域加强”的注浆理念进行注浆施工。通过现场实践,外堵内固注浆能达到注浆堵水和加固效果。外堵内固注浆与全断面帷幕注浆相比,注浆孔数量和注浆量减少50 %,在水量大时,注浆进度提高80 %,一般情况下提高50 %以上,因此,外堵内固注浆具有广阔的推广应用价值。

关键词: 高压富水断层     不均匀性     注浆堵水加固     外堵内固注浆     创新    

DX桩群桩承载性状的数值分析

张清林,陈立宏

《中国工程科学》 2012年 第14卷 第1期   页码 51-59

摘要:

通过数值计算对不同桩间距的DX桩群桩进行了分析研究。结果表明:DX桩的群桩效应随着桩间距的减小而逐渐明显,间距为6倍桩径的群桩极限承载力是间距为3倍桩径的群桩极限承载力的1.32倍;群桩间距由3倍桩径增大为6倍桩径时,群桩效应系数由0.59增大为0.78;群桩间土体沉降的最大值发生在两扩盘中间位置处,且随着桩间距的增大而减小。

关键词: DX桩     群桩     沉降     数值分析    

厦门翔安海底隧道F1风化深槽注浆加固技术

郭小红,王梦恕

《中国工程科学》 2011年 第13卷 第9期   页码 38-41

摘要:

以厦门翔安海底隧道涌水量最大、施工难度最大的海域段F1风化槽为研究对象,根据其围岩地质条件和突涌水特点,采用全断面注浆加固和堵水,注浆加固范围为掌子面内及隧道开挖轮廓线外5 m,隧道纵向加固长度为70 m,注浆材料以超细水泥单液浆为主的注浆加固方案。施工期现场监控量测与数值计算结果表明:F1风化深槽围岩注浆加固效果均较为理想,未发生涌水突泥,达到了设计的技术要求。该项研究成果为今后开展类似工程的注浆加固提供了技术借鉴。

关键词: 海底隧道     注浆加固     稳定性     数值仿真    

三峡升船机齿条及螺母柱间隙灌浆工艺试验

詹剑霞,李纪虎

《中国工程科学》 2013年 第15卷 第9期   页码 45-49

摘要:

为了选择出合适的灌浆材料和灌浆工艺并模拟升船机齿条、螺母柱间隙灌浆的实际情况,分别进行了灌浆工艺试验与原型灌浆试验。灌浆工艺试验对比了3种国产灌浆材料和德国PAGEL灌浆材料,试验结果表明德国PAGEL灌浆材料物理性能指标和力学性能指标优于国产灌浆材料。在原型灌浆试验中,对灌浆设备选型、搅拌时间、模板密封、灌浆方式、灌浆流速参数控制等方面进行了试验研究,优选出适用于三峡升船机齿条、螺母柱接缝灌浆的材料和合适的灌浆工艺。以上试验效果明显,解决了灌浆密封难度大、易堵管等施工难题。

关键词: 齿条     螺母柱     灌浆     升船机     三峡工程    

Optimum lateral extent of soil domain for dynamic SSI analysis of RC framed buildings on pile foundations

Nishant SHARMA, Kaustubh DASGUPTA, Arindam DEY

《结构与土木工程前沿(英文)》 2020年 第14卷 第1期   页码 62-81 doi: 10.1007/s11709-019-0570-2

摘要: This article describes a novel approach for deciding optimal horizontal extent of soil domain to be used for finite element based numerical dynamic soil structure interaction (SSI) studies. SSI model for a 12 storied building frame, supported on pile foundation-soil system, is developed in the finite element based software framework, OpenSEES. Three different structure-foundation configurations are analyzed under different ground motion characteristics. Lateral extent of soil domain, along with the soil properties, were varied exhaustively for a particular structural configuration. Based on the reduction in the variation of acceleration response at different locations in the SSI system (quantified by normalized root mean square error, ), the optimum lateral extent of the soil domain is prescribed for various structural widths, soil types and peak ground acceleration levels of ground motion. Compared to the past studies, error estimation analysis shows that the relationships prescribed in the present study are credible and more inclusive of the various factors that influence SSI. These relationships can be readily applied for deciding upon the lateral extent of the soil domain for conducting precise SSI analysis with reduced computational time.

关键词: soil structure interaction     optimum lateral extent of soil domain length     multi-storyed framed building     pile foundation     OpenSEES     L-K boundaries     dynamic analysis    

Influence of axial load on the lateral pile groups response in cohesionless and cohesive soil

Jasim M. ABBASA,Zamri CHIK,Mohd Raihan TAHA

《结构与土木工程前沿(英文)》 2015年 第9卷 第2期   页码 176-193 doi: 10.1007/s11709-015-0289-7

摘要: The lateral response of single and group of piles under simultaneous vertical and lateral loads has been analyzed using a 3D finite element approach. The response in this assessment considered lateral pile displacement and lateral soil resistance and corresponding - curve. As a result, modified - curves for lateral single pile response were improved with respect to the influence of increasing axial load intensities. The improved plots can be used for lateral loaded pile design and to produce the group action design -multiplier curves and equations. The effect of load combination on the lateral pile group response was performed on three pile group configurations (i.e., 2×1, 2×2 and 3×2) with four pile spacings (i.e., = 2 , 4 , 6 and 8 ). As a result, design curves were developed and applied on the actual case studies and similar expected cases for assessment of pile group behavior using improved p-multiplier. A design equation was derived from predicted design curves to be used in the evaluation of the lateral pile group action taking into account the effect of axial load intensities. It was found that the group interaction effect led to reduced lateral resistance for the pile in the group relative to that for the single pile in case of pure lateral load. While, in case of simultaneous combined loads, large axial load intensities (i.e., more than 6 , where is lateral load values) will have an increase in -multiplier by approximately 100% and will consequently contribute to greater group piles capacities.

关键词: piles     pile group     spacing     configuration     combined load    

DX桩单桩沉降分析

唐松涛,袁希雨,陈立宏

《中国工程科学》 2012年 第14卷 第1期   页码 41-45

摘要:

DX桩作为变截面桩型的典型代表,具有与普通直孔灌注桩不同的荷载传递机理,使桩基的承载力大大提高,沉降变形显著减小。多点支承的特点使得DX桩的沉降机理变得十分复杂,计算分析困难。通过对DX单桩沉降的实例分析,对DX桩与直孔桩的沉降特性进行对比,验证了设计规程中DX桩的沉降计算公式和修正系数的可靠性。

关键词: DX桩     直孔桩     沉降     修正系数    

标题 作者 时间 类型 操作

Experimental study on pile-end post-grouting piles for super-large bridge pile foundations

Weiming GONG, Guoliang DAI, Haowen ZHANG

期刊论文

DX桩与后压浆钻孔灌注桩现场试验研究

刘春刚,柴小兵,欧阳义,贺德新

期刊论文

大跨径悬索桥钢塔塔底钢混连接处承压板后压浆施工技术

张平,蒋建,董勤军,蔡伟,刘颖

期刊论文

Upgrading pyrolytic carbon-blacks (CBp) from end-of-life tires: Characteristics and modification methodologies

Jiaxue Yu, Junqing Xu, Zhenchen Li, Wenzhi He, Juwen Huang, Junshi Xu, Guangming Li

期刊论文

Topology-independent end-to-end learning model for improving the voltage profile in microgrids-integrated

期刊论文

Seismic performance of fabricated continuous girder bridge with grouting sleeve-prestressed tendon composite

期刊论文

Finite element prediction on the response of non-uniformly arranged pile groups considering progressivefailure of pile-soil system

Qian-Qing ZHANG, Shan-Wei LIU, Ruo-Feng FENG, Jian-Gu QIAN, Chun-Yu CUI

期刊论文

Efficacy and safety of JAK inhibitor INC424 in patients with primary and post-polycythemia vera or post-essential

null

期刊论文

高压富水断层“外堵内固注浆法”设计新理念与工程实践

张民庆,张梅

期刊论文

DX桩群桩承载性状的数值分析

张清林,陈立宏

期刊论文

厦门翔安海底隧道F1风化深槽注浆加固技术

郭小红,王梦恕

期刊论文

三峡升船机齿条及螺母柱间隙灌浆工艺试验

詹剑霞,李纪虎

期刊论文

Optimum lateral extent of soil domain for dynamic SSI analysis of RC framed buildings on pile foundations

Nishant SHARMA, Kaustubh DASGUPTA, Arindam DEY

期刊论文

Influence of axial load on the lateral pile groups response in cohesionless and cohesive soil

Jasim M. ABBASA,Zamri CHIK,Mohd Raihan TAHA

期刊论文

DX桩单桩沉降分析

唐松涛,袁希雨,陈立宏

期刊论文