资源类型

期刊论文 957

会议视频 19

年份

2023 67

2022 100

2021 79

2020 43

2019 49

2018 39

2017 37

2016 58

2015 48

2014 49

2013 43

2012 62

2011 38

2010 53

2009 41

2008 32

2007 40

2006 17

2005 8

2004 10

展开 ︾

关键词

水资源 16

细水雾 14

可持续发展 6

泥水盾构 6

反渗透 5

水环境 4

环境 4

砂卵石地层 4

绿色化工 4

超滤 4

三峡工程 3

优化 3

农业节水 3

半旱地农业 3

城镇建设 3

海上风电场 3

DX桩 2

Preissmann格式 2

中国西北地区 2

展开 ︾

检索范围:

排序: 展示方式:

Centrifuge model test and field measurement analysis for foundation pit with confined water

Chunlin DING , Xiaohong MENG ,

《结构与土木工程前沿(英文)》 2009年 第3卷 第3期   页码 299-304 doi: 10.1007/s11709-009-0035-0

摘要: The similarity law of centrifuge test was developed for the seepage field and stress field of a foundation pit with confined water by analyzing control equations, and a similarity index and a similarity coefficient of centrifuge test were obtained. Based on the deep foundation pit of the Huangxing Road Station of the Shanghai metro line M8, the deformation stability of the pit was tested. Finally, a comparative study was conducted on the test results of the pit deformation and the field measurement results. Comparison results show that the pit deformation regularity of the test is basically identical with that of the field measurement, and the difference in pit deformation between the test and the field measurement is within 50%. The centrifuge model test can effectively simulate the displacement response of the ground and retaining structure during dewatering and excavation for the pit with confined water, which provides a reliable basis for the design and construction of the pit with confined water.

关键词: foundation pit with confined water     centrifuge model test     seepage-stress coupling field     similarity relation     field measurement     deformation    

Influencing factors and control measures of excavation on adjacent bridge foundation based on analytic

Shuangxi FENG, Huayang LEI, Yongfeng WAN, Haiyan JIN, Jun HAN

《结构与土木工程前沿(英文)》 2021年 第15卷 第2期   页码 461-477 doi: 10.1007/s11709-021-0705-0

摘要: Many uncertain factors in the excavation process may lead to excessive lateral displacement or over-limited internal force of the piles, as well as inordinate settlement of soil surrounding the existing bridge foundation. Safety control is pivotal to ensuring the safety of adjacent structures. In this paper, an innovative method is proposed that combines an analytic hierarchy process (AHP) with a finite element method (FEM) to reveal the potential impact risk of uncertain factors on the surrounding environment. The AHP was adopted to determine key influencing factors based on the weight of each influencing factor. The FEM was used to quantify the impact of the key influencing factors on the surrounding environment. In terms of the AHP, the index system of uncertain factors was established based on an engineering investigation. A matrix comparing the lower index layer to the upper index layer, and the weight of each influencing factor, were calculated. It was found that the excavation depth and the distance between the foundation pit and the bridge foundation were fundamental factors. For the FEM, the FE baseline model was calibrated based on the case of no bridge surrounding the foundation pit. The consistency between the monitoring data and the numerical simulation data for a ground settlement was analyzed. FE simulations were then conducted to quantitatively analyze the degree of influence of the key influencing factors on the bridge foundation. Furthermore, the lateral displacement of the bridge pile foundation, the internal force of the piles, and the settlement of the soil surrounding the pile foundation were emphatically analyzed. The most hazardous construction condition was also determined. Finally, two safety control measures for increasing the numbers of support levels and the rooted depths of the enclosure structure were suggested. A novel method for combining AHP with FEM can be used to determine the key influencing aspects among many uncertain factors during a construction, which can provide some beneficial references for engineering design and construction.

关键词: deep foundation pit excavation     adjacent bridge foundation     influencing factors     analytic hierarchy process     finite element    

The influence of slope collapse on water exchange between a pit lake and a heterogeneous aquifer

Bo Zhang, Xilai Zheng, Tianyuan Zheng, Jia Xin, Shuai Sui, Di Zhang

《环境科学与工程前沿(英文)》 2019年 第13卷 第2期 doi: 10.1007/s11783-019-1104-9

摘要:

Slope collapse will reduce the water exchange.

Slope collapse will affect the spatial distribution of the water exchange.

Precipitation have the most impact on the dynamics of the water exchange.

关键词: Pit lake     Slope collapse     Groundwater–surface water interactions     Numerical simulation    

Interlayer-confined two-dimensional manganese oxide-carbon nanotube catalytic ozonation membrane forefficient water purification

《化学科学与工程前沿(英文)》 2022年 第16卷 第5期   页码 731-744 doi: 10.1007/s11705-021-2110-6

摘要: Catalytic ozonation technology has attracted copious attention in water purification owing to its favorable oxidative degradation of pollutants and mitigation of membrane fouling capacity. However, its extensive industrial application has been restricted by the low ozone utilization and limited mass transfer of the short-lived radical species. Interlayer space-confined catalysis has been theoretically proven to be a viable strategy for achieving high catalytic efficiency. Here, a two-dimensional MnO2-incorporated ceramic membrane with tunable interspacing, which was obtained via the intercalation of a carbon nanotube, was designed as a catalytic ozonation membrane reactor for degrading methylene blue. Benefiting from the abundant catalytic active sites on the surface of two-dimensional MnO2 as well as the ultralow mass transfer resistance of fluids due to the nanolayer confinement, an excellent mineralization effect, i.e., 1.2 mg O3(aq) mg–1 TOC removal (a total organic carbon removal rate of 71.5%), was achieved within a hydraulic retention time of 0.045 s of pollutant degradation. Further, the effects of hydraulic retention time and interlayer spacing on methylene blue removal were investigated. Moreover, the mechanism of the catalytic ozonation employing catalytic ozonation membrane was proposed based on the contribution of the Mn(III/IV) redox pair to electron transfer to generate the reactive oxygen species. This innovative two-dimensional confinement catalytic ozonation membrane could act as a nanoreactor and separator to efficiently oxidize organic pollutants and enhance the control of membrane fouling during water purification.

关键词: catalytic membrane reactor     catalytic ozonation     nanoconfinement     two-dimensional manganese oxide    

Consistency Guarantees for Professional Appraisal of Geotechnical Engineering Design under Market Leading and Deciding

Jian-ye Zheng

《工程管理前沿(英文)》 2015年 第2卷 第1期   页码 82-85 doi: 10.15302/J-FEM-2015012

摘要: Peer review is central to the process of modern engineering. Open peer review gives the impression that decisions are arrived at in a fair and meritocratic manner with an objective, reliable, consistent process. It is responsible for identifying methodological flaws and for improving the quality. Assistance from somebody in the same discipline is valuable. Clients refer to reviewers as referees since they help to determine the fate of a design. The client sets up a hanging committee to carry out open peer review to decide whether a piece of work should be accepted, revised or rejected. Reviewers in similar specialties make up a professional group. In an open peer review refereeing a retaining and protection structure design of building foundation pit excavation, an outside expert as an assessor, might master the art of review to pay attention to guarantee consistency of processes and outcomes.

关键词: peer review     foundation pit excavation     retaining and protection structure     design introduction    

青藏高原多年冻土地带爆破研究

何广沂

《中国工程科学》 2001年 第3卷 第6期   页码 57-64

摘要:

介绍了青藏高原多年冻土地带铁路试验工程中有关爆破方面的研究成果,针对多年冻土的特征,重点论述了爆破方法与工艺及先进实用的聚能爆破技术。

关键词: 多年冻土     路堑     基坑     钻孔     聚能弹     聚能爆破    

Shanghai Tower

Jian GONG

《工程管理前沿(英文)》 2017年 第4卷 第1期   页码 106-109 doi: 10.15302/J-FEM-2017001

摘要: Ru-jiang Zhao,Wung Hee Moh. [J]. Front. Eng, 2016, 3(2): 147-157.

关键词: super-high-rise building     green building     integral steel platform formwork system     large volume concrete     concrete pumped for super-high building     deep and large foundation pit     combined anterograde and retrograde methods     digitalized construction technology    

城市明挖地下工程开发环境效应研究现状及趋势

朱亦弘,徐日庆,龚晓南

《中国工程科学》 2017年 第19卷 第6期   页码 111-115 doi: 10.15302/J-SSCAE-2017.06.016

摘要:

随着城市地下空间开发规模不断增大,城市地下空间开发的主要矛盾从基坑自身稳定问题逐渐转向基坑周边环境变形控制问题。周边环境复杂情况下的地下空间开发极易引起地表不均匀沉降,建筑物开裂,造成巨大的经济损失。因此需要系统性地研究城市各类明挖基坑开发形式所带来的环境影响及环境效应控制技术。本文介绍和回顾了统计经验法、数值模拟法、模型试验法在明挖基坑引起的环境效应研究中取得的研究成果,总结了各类研究方法及成果的优势和不足。介绍了现有环境控制技术及应用案例,总结了地下空间开发环境效应研究成果,并对今后研究方向提出了建议。

关键词: 地下工程     明挖     基坑     环境效应     变形控制    

Shanghai center project excavation induced ground surface movements and deformations

Guolin XU, Jiwen ZHANG, Huang LIU, Changqin REN

《结构与土木工程前沿(英文)》 2018年 第12卷 第1期   页码 26-43 doi: 10.1007/s11709-017-0439-1

摘要: Empirical data on deep urban excavations can provide designers a significant reference basis for assessing potential deformations of the deep excavations and their impact on adjacent structures. The construction of the Shanghai Center involved excavations in excess of 33-m-deep using the top-down method at a site underlain by thick deposits of marine soft clay. A retaining system was achieved by 50-m-deep diaphragm walls with six levels of struts. During construction, a comprehensive instrumentation program lasting 14 months was conducted to monitor the behaviors of this deep circular excavation. The following main items related to ground surface movements and deformations were collected: (1) walls and circumferential soils lateral movements; (2) peripheral soil deflection in layers and ground settlements; and (3) pit basal heave. The results from the field instrumentation showed that deflections of the site were strictly controlled and had no large movements that might lead to damage to the stability of the foundation pit. The field performance of another 21cylindrical excavations in top-down method were collected to compare with this case through statistical analysis. In addition, numerical analyses were conducted to compare with the observed data. The extensively monitored data are characterized and analyzed in this paper.

关键词: deep excavation     foundation pit     soft clay     top-down method     field observation     ground surface movements     ground deformations    

大型深水沉井基础设计

陆勤丰,赵都桓,杨进

《中国工程科学》 2010年 第12卷 第4期   页码 9-13

摘要:

泰州大桥采用主跨为1 080 m三塔两跨悬索桥,中塔位于主江中心。通过对沉井基础和高桩承台钻孔桩基础等多项基础方案的比选,考虑到沉井结构受力明确、刚度大、工序简单,经济性高等优点,中塔基础最终选用沉井基础。根据塔柱底的构造要求,受力要求,沉井采用58 m×44 m四角倒圆的矩形沉井,沉井总高76 m。为了能在深水中顺利施工,沉井下部为钢壳混凝土结构,上部为钢筋混凝土结构。文中介绍了泰州大桥水中沉井的结构构造、施工方法、方案比较以及沉井的设计特点,可为今后类似工程起到很好的借鉴作用。

关键词: 泰州大桥     大型深水沉井     基础设计    

Development of deep neural network model to predict the compressive strength of FRCM confined columns

Khuong LE-NGUYEN; Quyen Cao MINH; Afaq AHMAD; Lanh Si HO

《结构与土木工程前沿(英文)》 2022年 第16卷 第10期   页码 1213-1232 doi: 10.1007/s11709-022-0880-7

摘要: The present study describes a reliability analysis of the strength model for predicting concrete columns confinement influence with Fabric-Reinforced Cementitious Matrix (FRCM). through both physical models and Deep Neural Network model (artificial neural network (ANN) with double and triple hidden layers). The database of 330 samples collected for the training model contains many important parameters, i.e., section type (circle or square), corner radius rc, unconfined concrete strength fco, thickness nt, the elastic modulus of fiber Ef , the elastic modulus of mortar Em. The results revealed that the proposed ANN models well predicted the compressive strength of FRCM with high prediction accuracy. The ANN model with double hidden layers (APDL-1) was shown to be the best to predict the compressive strength of FRCM confined columns compared with the ACI design code and five physical models. Furthermore, the results also reveal that the unconfined compressive strength of concrete, type of fiber mesh for FRCM, type of section, and the corner radius ratio, are the most significant input variables in the efficiency of FRCM confinement prediction. The performance of the proposed ANN models (including double and triple hidden layers) had high precision with R higher than 0.93 and RMSE smaller than 0.13, as compared with other models from the literature available.

关键词: FRCM     deep neural networks     confinement effect     strength model     confined concrete    

Fabrication of bimetallic Cu–Zn adsorbents with high dispersion by using confined space for gas adsorptive

《化学科学与工程前沿(英文)》   页码 1623-1631 doi: 10.1007/s11705-022-2202-y

摘要: The number of active components and their dispersion degree are two key factors affecting the performance of adsorbents. Here, we report a simple but efficient strategy for dispersing active components by using a confined space, which is formed by mesoporous silica walls and templates in the as-prepared SBA-15 (AS). Such a confined space does not exist in the conventional support, calcined SBA-15, which does not contain a template. The Cu and Zn precursors were introduced to the confined space in the AS and were converted to CuO and ZnO during calcination, during which the template was also removed. The results show that up to 5 mmol·g–1 of CuO and ZnO can be well dispersed; however, severe aggregation of both oxides takes place in the sample derived from the calcined SBA-15 with the same loading. Confined space in the AS and the strong interactions caused by the abundant hydroxyl groups are responsible for the dispersion of CuO and ZnO. The bimetallic materials were employed for the adsorptive separation of propene and propane. The samples prepared from the as-prepared SBA-15 showed superior performance to their counterparts from the calcined SBA-15 in terms of both adsorption capacity of propene and selectivity for propene/propane.

关键词: bimetallic adsorbents     confined space     mesoporous silica     propene/propane separation    

Fabrication of N-doped carbon nanobelts from a polypyrrole tube by confined pyrolysis for supercapacitors

Wei Wang, Haijun Lv, Juan Du, Aibing Chen

《化学科学与工程前沿(英文)》 2021年 第15卷 第5期   页码 1312-1321 doi: 10.1007/s11705-020-2033-7

摘要: In this present work, N-doped carbon nanobelts (N-CNBs) were prepared by a confined-pyrolysis approach and the N-CNBs were derived from a polypyrrole (Ppy) tube coated with a compact silica layer. The silica layer provided a confined space for the Ppy pyrolysis, thereby hindering the rapid overflow of pyrolysis gas, which is the activator for the formation of carbonaceous materials. At the same time, the confined environment can activate the carbon shell to create a thin wall and strip the carbon tube into belt morphology. This process of confined pyrolysis realizes self-activation during the pyrolysis of Ppy to obtain the carbon nanobelts without adding any additional activator, which reduces pollution and preparation cost. In addition, this approach is simple to operate and avoids the disadvantages of other methods that consume time and materials. The as-prepared N-CNB shows cross-linked nanobelt morphology and a rich porous structure with a large specific surface area. As supercapacitor electrode materials, the N-CNB can present abundant active sites, and exhibits a specific capacitance of 246 F·g , and excellent ability with 95.44% retention after 10000 cycles. This indicates that the N-CNB is an ideal candidate as a supercapacitor electrode material.

关键词: carbon nanobelts     polypyrrole     N-doped     confined pyrolysis     supercapacitor    

Ductility improvement of GFRP-RC beams using precast confined concrete block in compression zone

《结构与土木工程前沿(英文)》 doi: 10.1007/s11709-023-0968-8

摘要: Fiber-reinforced polymers (FRPs) have received considerable research attention because of their high strength, corrosion resistance, and low weight. However, owing to the lack of ductility in this material and the quasi-brittle behavior of concrete, FRP-reinforced concrete (FRP-RC) beams, even with flexural failure, do not fail in a ductile manner. Because the limited deformation capacity of FRP-RC beams depends on the ductility of their compression zones, the present study proposes using a precast confined concrete block (PCCB) in the compression zone to improve the ductility of the beams. A control beam and four beams with different PCCBs were cast and tested under four-point bending conditions. The control beam failed due to shear, and the PCCBs exhibited different confinements and perforations. The goal was to find an appropriate PCCB for use in the compression zone of the beams, which not only improved the ductility but also changed the failure mode of the beams from shear to flexural. Among the employed blocks, a ductile PCCB with low equivalent compressive strength increased the ductility ratio of the beam to twice that of the control beam. The beam failed in pure flexure with considerable deformation capacity and without significant stiffness reduction.

关键词: ductility     four-point bending test     glass fiber-reinforced polymer     precast confined concrete block    

Confined masonry as practical seismic construction alternative–the experience from the 2014 Cephalonia

Fillitsa KARANTONI, Stavroula PANTAZOPOULOU, Athanasios GANAS

《结构与土木工程前沿(英文)》 2018年 第12卷 第3期   页码 270-290 doi: 10.1007/s11709-017-0390-1

摘要:

During August 1953 three strong earthquakes of magnitude ranging from 6.3 to 7.2 shook the Ionian Island of Cephalonia (Kefalonia), Greece, and destroyed almost the entire building stock of the Island which consisted primarily of traditional unreinforced masonry (URM) houses. The authorities went on to restructuring of the building stock, using a structural system that is most like what is known today as confined masonry. They designed about 14 types of one- to two-storey buildings providing the engineers with detailed construction plans. These buildings are known as “Arogi” buildings (Arogi in Greek meaning Aid). On the 24th of January and 3rd of February 2014, two earthquakes of magnitude 6.1 and 6.0 struck the island, causing significant soil damages, developing excessively high ground accelerations. Surprisingly, no damage was reported in the “Arogi” buildings. The seismic behavior of the buildings is examined by FEM linear analysis and it is compared to that of URM structures. Computed results illustrate that the displacements of identical URM buildings would be about twice the magnitudes observed in the corresponding “Arogi” ones, with the implication that the earthquake sequence of 2014 would have caused critical damage should the type of structure be of the URM type. Furthermore, it is illustrated that this low cost alternative method of construction is a very effective means of producing earthquake resilient structures, whereas further reduction of seismic displacement may be achieved in the order of 50% with commensurate effects on damage potential, when reinforced slabs are used to replace the timber roofs.

关键词: Cephalonia     confined masonry     comparative FEM analysis     unreinforced masonry     seismic damage    

标题 作者 时间 类型 操作

Centrifuge model test and field measurement analysis for foundation pit with confined water

Chunlin DING , Xiaohong MENG ,

期刊论文

Influencing factors and control measures of excavation on adjacent bridge foundation based on analytic

Shuangxi FENG, Huayang LEI, Yongfeng WAN, Haiyan JIN, Jun HAN

期刊论文

The influence of slope collapse on water exchange between a pit lake and a heterogeneous aquifer

Bo Zhang, Xilai Zheng, Tianyuan Zheng, Jia Xin, Shuai Sui, Di Zhang

期刊论文

Interlayer-confined two-dimensional manganese oxide-carbon nanotube catalytic ozonation membrane forefficient water purification

期刊论文

Consistency Guarantees for Professional Appraisal of Geotechnical Engineering Design under Market Leading and Deciding

Jian-ye Zheng

期刊论文

青藏高原多年冻土地带爆破研究

何广沂

期刊论文

Shanghai Tower

Jian GONG

期刊论文

城市明挖地下工程开发环境效应研究现状及趋势

朱亦弘,徐日庆,龚晓南

期刊论文

Shanghai center project excavation induced ground surface movements and deformations

Guolin XU, Jiwen ZHANG, Huang LIU, Changqin REN

期刊论文

大型深水沉井基础设计

陆勤丰,赵都桓,杨进

期刊论文

Development of deep neural network model to predict the compressive strength of FRCM confined columns

Khuong LE-NGUYEN; Quyen Cao MINH; Afaq AHMAD; Lanh Si HO

期刊论文

Fabrication of bimetallic Cu–Zn adsorbents with high dispersion by using confined space for gas adsorptive

期刊论文

Fabrication of N-doped carbon nanobelts from a polypyrrole tube by confined pyrolysis for supercapacitors

Wei Wang, Haijun Lv, Juan Du, Aibing Chen

期刊论文

Ductility improvement of GFRP-RC beams using precast confined concrete block in compression zone

期刊论文

Confined masonry as practical seismic construction alternative–the experience from the 2014 Cephalonia

Fillitsa KARANTONI, Stavroula PANTAZOPOULOU, Athanasios GANAS

期刊论文