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Quality Control Measures of Bored Pile in Bridge Construction
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作者 Lin Nan Guangjun Li +3 位作者 Yan Liu Xu Meng Yingying Ye Zhongyang Sun 《Journal of World Architecture》 2023年第2期47-52,共6页
In order to improve the quality of bored piles in bridge construction and ensure the overall quality of the bridge,we analyzed a series of problems in the construction process of bored piles,then propose corresponding... In order to improve the quality of bored piles in bridge construction and ensure the overall quality of the bridge,we analyzed a series of problems in the construction process of bored piles,then propose corresponding quality control measures,in hopes of improving quality control of bored piles in bridge construction in our country. 展开更多
关键词 Bridge construction bored pile Quality control
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Experimental study and numerical analysis on bearing behaviors of super-long rock-socketed bored pile groups 被引量:2
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作者 高睿 胡念 朱斌 《Journal of Southeast University(English Edition)》 EI CAS 2010年第4期597-602,共6页
A centrifuge modeling test and a three-dimensional finite element analysis(FEA)of super-long rock-socketed bored pile groups of the Tianxingzhou Bridge are proposed.Based on the similarity theory,different prototypi... A centrifuge modeling test and a three-dimensional finite element analysis(FEA)of super-long rock-socketed bored pile groups of the Tianxingzhou Bridge are proposed.Based on the similarity theory,different prototypical materials are simulated using different indicators in the centrifuge model.The silver sand,the shaft and the pile cap are simulated according to the natural density,the compressive stiffness and the bending stiffness,respectively.The finite element method(FEM)is implemented and analyzed in ANSYS,in which the stress field during the undisturbed soil stage,the boring stage,the concrete-casting stage and the curing stage are discussed in detail.Comparisons in terms of load-settlement,shaft axial force distribution and lateral friction between the numerical results and the test data are carried out to investigate the bearing behaviors of super-long rock-socketed bored pile groups under loading and unloading conditions.Results show that there is a good agreement between the centrifuge modeling tests and the FEM.In addition,the load distribution at the pile top is complicated,which is related to the stiffness of the cap,the corresponding assumptions and the analysis method.The shaft axial force first increases slightly with depth then decreases sharply,and the rate of decrease in rock is greater than that in sand and soil. 展开更多
关键词 super-long rock-socketed pile bored pile groups centrifuge modeling test finite element analysis
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A case study on behaviors of composite soil nailed wall with bored piles in a deep excavation 被引量:7
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作者 ZHU Feng-bin MIAO Lin-chang +1 位作者 GU Huan-da CHENG Yue-hong 《Journal of Central South University》 SCIE EI CAS 2013年第7期2017-2024,共8页
A complete case of a deep excavation was explored. According to the practical working conditions, a 3D non-linear finite element procedure is used to simulate a deep excavation supported by the composite soil nailed w... A complete case of a deep excavation was explored. According to the practical working conditions, a 3D non-linear finite element procedure is used to simulate a deep excavation supported by the composite soil nailed wall with bored piles in soft soil. The modified cam clay model is employed as the constitutive relationship of the soil in the numerical simulation. Results from the numerical analysis are fitted well with the field data, which indicate that the research approach used is reliable. Based on the field data and numerical results of the deep excavation supported by four different patterns of the composite soil nailed wall, the significant corner effect is founded in the 3D deep excavation. If bored piles or soil anchors are considered in the composite soil nailed wall, they are beneficial to decreasing deformations and internal forces of bored piles, cement mixing piles, soil anchors, soil nailings and soil around the deep excavation. Besides, the effects due to bored piles are more significant than those deduced from soil anchors. All mentioned above prove that the composite soil nailed wall with bored piles is feasible in the deep excavation. 展开更多
关键词 deep excavation 3D non-linear finite element bored pile composite soil nailed wall corner effect DEFORMATION internal force
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Regressive approach for predicting bearing capacity of bored piles from cone penetration test data 被引量:3
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作者 Iyad S. Alkroosh Mohammad Bahadori +1 位作者 Hamid Nikraz Alireza Bahadori 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2015年第5期584-592,共9页
In this study, th e least sq u are su p p o rt v ecto r m achine (LSSVM) alg o rith m w as applied to predicting th ebearing capacity o f b ored piles e m b ed d ed in sand an d m ixed soils. Pile g eo m etry an d c... In this study, th e least sq u are su p p o rt v ecto r m achine (LSSVM) alg o rith m w as applied to predicting th ebearing capacity o f b ored piles e m b ed d ed in sand an d m ixed soils. Pile g eo m etry an d cone p e n e tra tio nte s t (CPT) resu lts w ere used as in p u t variables for pred ictio n o f pile bearin g capacity. The d ata u se d w erecollected from th e existing litera tu re an d consisted o f 50 case records. The application o f LSSVM w ascarried o u t by dividing th e d ata into th re e se ts: a train in g se t for learning th e pro b lem an d obtain in g arelationship b e tw e e n in p u t variables an d pile bearin g capacity, and testin g an d validation sets forevaluation o f th e predictive an d g en eralization ability o f th e o b tain ed relationship. The predictions o f pilebearing capacity by LSSVM w ere evaluated by com paring w ith ex p erim en tal d ata an d w ith th o se bytrad itio n al CPT-based m eth o d s and th e gene ex pression pro g ram m in g (GEP) m odel. It w as found th a t th eLSSVM perform s w ell w ith coefficient o f d eterm in atio n , m ean, an d sta n d ard dev iatio n equivalent to 0.99,1.03, an d 0.08, respectively, for th e testin g set, an d 1, 1.04, an d 0.11, respectively, for th e v alidation set. Thelow values o f th e calculated m ean squared e rro r an d m ean ab so lu te e rro r indicated th a t th e LSSVM w asaccurate in p redicting th e pile bearing capacity. The results o f com parison also show ed th a t th e p roposedalg o rith m p red icted th e pile bearin g capacity m ore accurately th a n th e trad itio n al m eth o d s including th eGEP m odel. 展开更多
关键词 bored piles Cone penetration test(CPT) Bearing capacity Least square support vector machine(LSSVM) TRAINING VALIDATION
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Dynamic estimation and reliability control of quality assurance for bored piles
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作者 赵文艺 徐志军 +1 位作者 郑俊杰 边晓亚 《Journal of Central South University》 SCIE EI CAS 2014年第3期1148-1157,共10页
A systematic method was proposed to estimate the occurrence probability of defective piles(OPDP) from a site according to quality assurance inspection. The OPDP was firstly suggested as the criterion to weight the per... A systematic method was proposed to estimate the occurrence probability of defective piles(OPDP) from a site according to quality assurance inspection. The OPDP was firstly suggested as the criterion to weight the performance of a pile foundation. Its prior distribution and updating distribution were deduced to follow Beta distributions. To calibrate the OPDP, a dynamic estimation model was established according to the relationships between prior mean and variance and updating mean and variance. Finally, a reliability-control method dealing with uncertainties arising from quality assurance inspection was formalized to judge whether all the bored piles from a site can be accepted. It is exemplified that the OPDP can be substantially improved when more definite prior information and sampling formation become available. For the example studied herein, the Bayesian estimator of updating variance for OPDP is reduced from 0.0037 to 0.0014 for the first inspection, from 0.0014 to 0.0009 for the second inspection, and with less uncertainty by incorporating experience information. 展开更多
关键词 bored piles quality assurance inspection reliability control occurrence probability Bayesian method
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Study on influence of ground settlement in bored metro tunnel
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作者 方江华 张志红 《Journal of Coal Science & Engineering(China)》 2006年第2期27-29,共3页
At present the bored construction method is one of the main construction methods of metro and tunnel construction in China. The empirical estimated formulas of tunnel ground surface settlement using the bored construc... At present the bored construction method is one of the main construction methods of metro and tunnel construction in China. The empirical estimated formulas of tunnel ground surface settlement using the bored construction method were obtained, combining the mechanical stimulant calculated result of tunnel model of different embedded depth, different cross section and different construction method and the actual measurement data of Beijing metro construction. According to the regressed analysis of calculated data, the calculated equations of ground surface settlement value and settlement range of tunnel section under the condition of different embedded depth, different cross section and different construction method were gained. Among them there are some empirical formulas can apply to the construction design of metro tunnel directly. 展开更多
关键词 bored construction method ground settlement settlement groove width modulus settlement range
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Comparative Examinations of Single Bored Piles Using International Codes
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作者 Mohamed Mosad El-Gendy Ibrahim A. El Araby Mohamed A. Kamal 《Engineering(科研)》 2013年第10期796-806,共11页
This paper presents some aspects of the load-settlement behavior for large diameter bored piles using four different international codes, namely: ECP 202 [1], DIN 4014 [2], AASHTO [3] and French Code [4]. Ultimate cap... This paper presents some aspects of the load-settlement behavior for large diameter bored piles using four different international codes, namely: ECP 202 [1], DIN 4014 [2], AASHTO [3] and French Code [4]. Ultimate capacities for 38 pile load tests founded in realistic multi-layered soils in Delta and Port Saidareas atEgyptare evaluated using modified Chin (1970) method and compared to ultimate load predictions obtained by the aforementioned codes. Many statistical analyses were conducted on the total pile loads and individual contributions of tip and skin resistances. Based on code predictions of ultimate pile loads, an empirical modified load-settlement model is proposed. This model will simplify to a great extent the analysis of piled-raft systems as it can effortlessly predict pile settlement due to the load on pile itself. Comparisons showed that the pile load test is an irreplaceable process for determining the ultimate capacity of piles. 展开更多
关键词 bored PILES ULTIMATE PILE Load International CODES Empirical Function
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Why Are Children Bored at School?
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作者 Mika 《新世纪智能》 2018年第3期35-36,共2页
词数:345阅读难度:建议阅读时间:4分钟Well,it used to be fun.It used to be about fun and rest,but now we’re just running across the school to get to the fourth period.We used to go home and see our families but now it’... 词数:345阅读难度:建议阅读时间:4分钟Well,it used to be fun.It used to be about fun and rest,but now we’re just running across the school to get to the fourth period.We used to go home and see our families but now it’s being in a dorm with some random doofus who steals your food.It used to be about easy assignments and times tables,but 展开更多
关键词 Why Are Children bored at School
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开挖补偿法防控深部地下岩爆灾害——引汉济渭工程秦岭输水隧洞案例分析 被引量:1
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作者 Jie Hu Manchao He +4 位作者 Hongru Li Zhigang Tao Dongqiao Liu Tai Cheng Di Peng 《Engineering》 SCIE EI CAS CSCD 2024年第3期154-163,共10页
Rockburst disasters occur frequently during deep underground excavation,yet traditional concepts and methods can hardly meet the requirements for support under high geo-stress conditions.Consequently,rockburst control... Rockburst disasters occur frequently during deep underground excavation,yet traditional concepts and methods can hardly meet the requirements for support under high geo-stress conditions.Consequently,rockburst control remains challenging in the engineering field.In this study,the mechanism of excavation-induced rockburst was briefly described,and it was proposed to apply the excavation compensation method(ECM)to rockburst control.Moreover,a field test was carried out on the Qinling Water Conveyance Tunnel.The following beneficial findings were obtained:Excavation leads to changes in the engineering stress state of surrounding rock and results in the generation of excess energy DE,which is the fundamental cause of rockburst.The ECM,which aims to offset the deep excavation effect and lower the risk of rockburst,is an active support strategy based on high pre-stress compensation.The new negative Poisson’s ratio(NPR)bolt developed has the mechanical characteristics of high strength,high toughness,and impact resistance,serving as the material basis for the ECM.The field test results reveal that the ECM and the NPR bolt succeed in controlling rockburst disasters effectively.The research results are expected to provide guidance for rockburst support in deep underground projects such as Sichuan-Xizang Railway. 展开更多
关键词 ROCKBURST Excavation compensation method Pre-stressed support Negative Poisson’s ratio bolt Tunnel boring machine
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Hydrodynamic Characteristics of Undular Tidal Bores in the Qiantang River Based on Field Observations
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作者 ZHANG Shu-yu PAN Cun-hong +3 位作者 ZHANG Shen-yang LI Ruo-hua CHENG Wenlong XIE Dong-feng 《China Ocean Engineering》 SCIE EI CSCD 2024年第3期505-518,共14页
Understanding the undular tidal bores in the Qiantang River is essential for effective river management and maintenance.While breaking tidal bores have been studied extensively, reports on undular tidal bores in the Q... Understanding the undular tidal bores in the Qiantang River is essential for effective river management and maintenance.While breaking tidal bores have been studied extensively, reports on undular tidal bores in the Qiantang Riverremain limited. Furthermore, observed data on undular tidal bores fulfilling the requirements of short measurementtime intervals, and spring, medium, and neap tide coverage, and providing detailed data for the global vertical stratificationof flow velocity are quite limited. Based on field observations at Qige in the Qiantang estuary, we analyzedthe characteristics of undular tidal bores. The results showed that the flooding amplitude (a) of the first wave isalways larger than its ebbing amplitude (b). Moreover, the vertical distribution of the maximum flood velocity exhibitesthree shapes, influenced by the tidal range, while that of the maximum ebb velocity exhibites a single shape. Duringthe initial phase of the flood tide in the spring and medium tides, the upper water body experiences multiple oscillatingchanges along the flow direction, corresponding to the alternating process of the crest and trough of the tide levelupon the arrival of the tidal bore. The tidal range is a crucial parameter in tidal bore hydrodynamics. By establishingthe relationship between hydrodynamic parameters and tidal range, other hydrodynamic parameters, such as the tidalbore height, maximum flood depth–averaged velocity, maximum flood stratified velocity at the measurement points,and duration of the flood tide current, can be effectively predicted, thereby providing an important reference for rivermanagement and maintenance. 展开更多
关键词 tidal bores Qiantang Estuary tidal bore height tidal bore velocity propagation speed
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An Optimized System of Random Forest Model by Global Harmony Search with Generalized Opposition-Based Learning for Forecasting TBM Advance Rate
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作者 Yingui Qiu Shuai Huang +3 位作者 Danial Jahed Armaghani Biswajeet Pradhan Annan Zhou Jian Zhou 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第3期2873-2897,共25页
As massive underground projects have become popular in dense urban cities,a problem has arisen:which model predicts the best for Tunnel Boring Machine(TBM)performance in these tunneling projects?However,performance le... As massive underground projects have become popular in dense urban cities,a problem has arisen:which model predicts the best for Tunnel Boring Machine(TBM)performance in these tunneling projects?However,performance level of TBMs in complex geological conditions is still a great challenge for practitioners and researchers.On the other hand,a reliable and accurate prediction of TBM performance is essential to planning an applicable tunnel construction schedule.The performance of TBM is very difficult to estimate due to various geotechnical and geological factors and machine specifications.The previously-proposed intelligent techniques in this field are mostly based on a single or base model with a low level of accuracy.Hence,this study aims to introduce a hybrid randomforest(RF)technique optimized by global harmony search with generalized oppositionbased learning(GOGHS)for forecasting TBM advance rate(AR).Optimizing the RF hyper-parameters in terms of,e.g.,tree number and maximum tree depth is the main objective of using the GOGHS-RF model.In the modelling of this study,a comprehensive databasewith themost influential parameters onTBMtogetherwithTBM AR were used as input and output variables,respectively.To examine the capability and power of the GOGHSRF model,three more hybrid models of particle swarm optimization-RF,genetic algorithm-RF and artificial bee colony-RF were also constructed to forecast TBM AR.Evaluation of the developed models was performed by calculating several performance indices,including determination coefficient(R2),root-mean-square-error(RMSE),and mean-absolute-percentage-error(MAPE).The results showed that theGOGHS-RF is a more accurate technique for estimatingTBMAR compared to the other applied models.The newly-developedGOGHS-RFmodel enjoyed R2=0.9937 and 0.9844,respectively,for train and test stages,which are higher than a pre-developed RF.Also,the importance of the input parameters was interpreted through the SHapley Additive exPlanations(SHAP)method,and it was found that thrust force per cutter is the most important variable on TBMAR.The GOGHS-RF model can be used in mechanized tunnel projects for predicting and checking performance. 展开更多
关键词 Tunnel boring machine random forest GOGHS optimization PSO optimization GA optimization ABC optimization SHAP
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A performance-based hybrid deep learning model for predicting TBM advance rate using Attention-ResNet-LSTM
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作者 Sihao Yu Zixin Zhang +2 位作者 Shuaifeng Wang Xin Huang Qinghua Lei 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第1期65-80,共16页
The technology of tunnel boring machine(TBM)has been widely applied for underground construction worldwide;however,how to ensure the TBM tunneling process safe and efficient remains a major concern.Advance rate is a k... The technology of tunnel boring machine(TBM)has been widely applied for underground construction worldwide;however,how to ensure the TBM tunneling process safe and efficient remains a major concern.Advance rate is a key parameter of TBM operation and reflects the TBM-ground interaction,for which a reliable prediction helps optimize the TBM performance.Here,we develop a hybrid neural network model,called Attention-ResNet-LSTM,for accurate prediction of the TBM advance rate.A database including geological properties and TBM operational parameters from the Yangtze River Natural Gas Pipeline Project is used to train and test this deep learning model.The evolutionary polynomial regression method is adopted to aid the selection of input parameters.The results of numerical exper-iments show that our Attention-ResNet-LSTM model outperforms other commonly-used intelligent models with a lower root mean square error and a lower mean absolute percentage error.Further,parametric analyses are conducted to explore the effects of the sequence length of historical data and the model architecture on the prediction accuracy.A correlation analysis between the input and output parameters is also implemented to provide guidance for adjusting relevant TBM operational parameters.The performance of our hybrid intelligent model is demonstrated in a case study of TBM tunneling through a complex ground with variable strata.Finally,data collected from the Baimang River Tunnel Project in Shenzhen of China are used to further test the generalization of our model.The results indicate that,compared to the conventional ResNet-LSTM model,our model has a better predictive capability for scenarios with unknown datasets due to its self-adaptive characteristic. 展开更多
关键词 Tunnel boring machine(TBM) Advance rate Deep learning Attention-ResNet-LSTM Evolutionary polynomial regression
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Effects of data smoothing and recurrent neural network(RNN)algorithms for real-time forecasting of tunnel boring machine(TBM)performance
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作者 Feng Shan Xuzhen He +1 位作者 Danial Jahed Armaghani Daichao Sheng 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第5期1538-1551,共14页
Tunnel boring machines(TBMs)have been widely utilised in tunnel construction due to their high efficiency and reliability.Accurately predicting TBM performance can improve project time management,cost control,and risk... Tunnel boring machines(TBMs)have been widely utilised in tunnel construction due to their high efficiency and reliability.Accurately predicting TBM performance can improve project time management,cost control,and risk management.This study aims to use deep learning to develop real-time models for predicting the penetration rate(PR).The models are built using data from the Changsha metro project,and their performances are evaluated using unseen data from the Zhengzhou Metro project.In one-step forecast,the predicted penetration rate follows the trend of the measured penetration rate in both training and testing.The autoregressive integrated moving average(ARIMA)model is compared with the recurrent neural network(RNN)model.The results show that univariate models,which only consider historical penetration rate itself,perform better than multivariate models that take into account multiple geological and operational parameters(GEO and OP).Next,an RNN variant combining time series of penetration rate with the last-step geological and operational parameters is developed,and it performs better than other models.A sensitivity analysis shows that the penetration rate is the most important parameter,while other parameters have a smaller impact on time series forecasting.It is also found that smoothed data are easier to predict with high accuracy.Nevertheless,over-simplified data can lose real characteristics in time series.In conclusion,the RNN variant can accurately predict the next-step penetration rate,and data smoothing is crucial in time series forecasting.This study provides practical guidance for TBM performance forecasting in practical engineering. 展开更多
关键词 Tunnel boring machine(TBM) Penetration rate(PR) Time series forecasting Recurrent neural network(RNN)
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Determination of large diameter bored pile's effective length based on Mindlin's solution
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作者 Zhijun Zhou Duanduan Wang +1 位作者 Lipeng Zhang Weisi Ma 《Journal of Traffic and Transportation Engineering(English Edition)》 2015年第6期422-428,共7页
The calculation equation of large diameter bored pile's effective length is connected with its distribution of pile shaft resistance. Thus, there is a great difference between the calculation results under the differ... The calculation equation of large diameter bored pile's effective length is connected with its distribution of pile shaft resistance. Thus, there is a great difference between the calculation results under the different distributions of pile shaft resistance. Primarily, this paper summarizes the conceptualized mode of pile shaft resistance under the circum- stance that the soil surrounding the piles presents different layer distributions. Secondly, based on Mindlin's displacement solution and in consideration of the effect of pile diam- eter, the calculation equation is optimized with the assumption that the pile shaft resis- tance has a parabolic distribution. The influencing factors are analyzed according to the calculation result of effective pile length. Finally, combined with an engineering example, the calculation equation deduced in this paper is analyzed and verified. The result shows that both the Poisson ratio of soil and pile diameter have impacted the effective pile length. Compared with the Poisson ratio of soil, the effect of pile diameter is more significant. If the pile diameter remains the same, the effect of the Poisson ratio of soil to the effective pile length decreases as the ratio of pile elastic modulus and soil share modulus increases. If the Poisson ratio of soil remains the same, the effect of the pile diameter to the effective pile length increases as the ratio of pile elastic modulus and soil share modulus increases. Thus the optimized calculation result of pile effective length under the consideration of pile diameter effect is more close to the actual situation of engineering and reasonably practicable. 展开更多
关键词 Large diameter bored pile Pile shaft resistance Parabolic distribution Mindlin's solution Effect of pile diameter Effective pile length
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复合地层小直径隧道掘进机掘进速度区间预测 被引量:1
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作者 杨耀红 韩兴忠 +2 位作者 张智晓 刘德福 孙小虎 《科学技术与工程》 北大核心 2023年第34期14638-14650,共13页
合理准确预测隧道掘进机(tunnel boring machine,TBM)的掘进速度是实现TBM智能化控制的关键问题之一,复合地层小直径TBM施工的不确定性较常规地质条件更强,而传统预测方法对施工过程的不确定性考虑不足。在此通过引入区间预测方法,提出... 合理准确预测隧道掘进机(tunnel boring machine,TBM)的掘进速度是实现TBM智能化控制的关键问题之一,复合地层小直径TBM施工的不确定性较常规地质条件更强,而传统预测方法对施工过程的不确定性考虑不足。在此通过引入区间预测方法,提出基于4种不同Bootstrap方法结合KELM-ANN模型的TBM掘进速度区间预测模型,并以南水北调安阳输水隧洞工程为例,选取142组工程实测数据验证区间预测模型的有效性。研究结果表明:基于Rademacher分布建立的模型预测结果优于其他3种方法,不仅可以得到较好的点预测结果,还可以构造出较为清晰可靠的区间将掘进速度实测值完全包络在内;随着置信水平的提高,区间可容纳的不确定性和风险也逐渐上升,通过变化区间宽度,能较好地量化和解释TBM施工过程中的不确定性因素对掘进速度的影响。研究结果可为TBM掘进性能预测和掘进参数优化提供参考。 展开更多
关键词 复合地层 小直径隧道掘进机(tunnel boring machine TBM) 掘进速度 区间预测 BOOTSTRAP方法 核极限学习机(kernel based extreme learning machine KELM) 神经网络
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Vibrations induced by tunnel boring machine in urban areas: In situ measurements and methodology of analysis 被引量:3
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作者 Antoine Rallu Nicolas Berthoz +1 位作者 Simon Charlemagne Denis Branque 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2023年第1期130-145,共16页
Excavation with tunnel boring machine(TBM)can generate vibrations,causing damages to neighbouring buildings and disturbing the residents or the equipment.This problem is particularly challenging in urban areas,where T... Excavation with tunnel boring machine(TBM)can generate vibrations,causing damages to neighbouring buildings and disturbing the residents or the equipment.This problem is particularly challenging in urban areas,where TBMs are increasingly large in diameter and shallow in depth.In response to this problem,four experimental campaigns were carried out in different geotechnical contexts in France.The vibration measurements were acquired on the surface and inside the TBMs.These measurements are also complemented by few data in the literature.An original methodology of signal processing is pro-posed to characterize the amplitude of the particle velocities,as well as the frequency content of the signals to highlight the most energetic bands.The levels of vibrations are also compared with the thresholds existing in various European regulations concerning the impact on neighbouring structures and the disturbance to local residents. 展开更多
关键词 Ground-borne vibrations Tunnel boring machine(TBM) In situ measurement Dynamic characterization Vibration levels Site spectrum
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Tunnelling performance prediction of cantilever boring machine in sedimentary hard-rock tunnel using deep belief network 被引量:2
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作者 SONG Zhan-ping CHENG Yun +1 位作者 ZHANG Ze-kun YANG Teng-tian 《Journal of Mountain Science》 SCIE CSCD 2023年第7期2029-2040,共12页
Evaluating the adaptability of cantilever boring machine(CBM) through in-depth excavation and analysis of tunnel excavation data and rock mass parameters is the premise of mechanical design and efficient excavation in... Evaluating the adaptability of cantilever boring machine(CBM) through in-depth excavation and analysis of tunnel excavation data and rock mass parameters is the premise of mechanical design and efficient excavation in the field of underground space engineering.This paper presented a case study of tunnelling performance prediction method of CBM in sedimentary hard-rock tunnel of Karst landform type by using tunneling data and surrounding rock parameters.The uniaxial compressive strength(UCS),rock integrity factor(Kv),basic quality index([BQ]),rock quality index RQD,brazilian tensile strength(BTS) and brittleness index(BI) were introduced to construct a performance prediction database based on the hard-rock tunnel of Guiyang Metro Line 1 and Line 3,and then established the performance prediction model of cantilever boring machine.Then the deep belief network(DBN) was introduced into the performance prediction model,and the reliability of performance prediction model was verified by combining with engineering data.The study showed that the influence degree of surrounding rock parameters on the tunneling performance of the cantilever boring machine is UCS > [BQ] > BTS >RQD > Kv > BI.The performance prediction model shows that the instantaneous cutting rate(ICR) has a good correlation with the surrounding rock parameters,and the predicting model accuracy is related to the reliability of construction data.The prediction of limestone and dolomite sections of Line 3 based on the DBN performance prediction model shows that the measured ICR and predicted ICR is consistent and the built performance prediction model is reliable.The research results have theoretical reference significance for the applicability analysis and mechanical selection of cantilever boring machine for hard rock tunnel. 展开更多
关键词 Urban metro tunnel Cantilever boring machine Hard rock tunnel Performance prediction model Linear regression Deep belief network
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基于PSO-LSSVM算法的隧道掘进机掘进参数预测方法 被引量:3
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作者 李宏波 张冬月 葛学元 《科学技术与工程》 北大核心 2023年第14期6230-6237,共8页
为了规避隧道掘进机(tunnel boring machine,TBM)掘进参数人为设定的主观性,提出了一种基于粒子群-最小二乘支持向量机算法(PSO-LSSVM)的TBM掘进参数预测方法。通过从海量TBM工程掘进数据中探寻参数变化规律,降低了TBM主司机设定掘进参... 为了规避隧道掘进机(tunnel boring machine,TBM)掘进参数人为设定的主观性,提出了一种基于粒子群-最小二乘支持向量机算法(PSO-LSSVM)的TBM掘进参数预测方法。通过从海量TBM工程掘进数据中探寻参数变化规律,降低了TBM主司机设定掘进参数的主观性,辅助其合理选择掘进参数,有利于提高掘进效率、规避工程风险,经实验和工程数据验证,PSO-LSSVM算法通过对样本粒子全局迭代寻优来优化参数,提升了预测算法泛化能力和预测精度,对推力、扭矩和推进速度参数预测数值偏差满足要求,可辅助指导主司机设定掘进参数。 展开更多
关键词 隧道掘进机(tunnel boring machine TBM) 掘进参数 粒子群(particle swarm optimization PSO) 支持向量机(support vector machine SVM) 参数预测
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Flume Experiment Investigation on Propagation Characteristics of Tidal Bore in A Curved Channel
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作者 FAN Jun TAO Ai-feng +2 位作者 SHI Mo-quan LI Ying PENG Ji 《China Ocean Engineering》 SCIE EI CSCD 2023年第1期131-144,共14页
Tidal bore is a special and intensive form of flow movement induced by tidal effect in estuary areas, which has complex characteristics of profile, propagation and flow velocity. Although it has been widely studied fo... Tidal bore is a special and intensive form of flow movement induced by tidal effect in estuary areas, which has complex characteristics of profile, propagation and flow velocity. Although it has been widely studied for the generation mechanism, propagation features and influencing factors, the curved channel will complicate the characteristics of tidal bore propagation, which need further investigation compared with straight channel. In this study, the flume experiments for both undular and breaking bores’ propagation in curved channel are performed to measure the freesurface elevation and flow velocity by ultrasonic sensors and ADV respectively. The propagation characteristics,including tidal bore height, cross-section surface gradient, tidal bore propagation celerity, and flow velocity are obtained for both sides of the curved channel. And three bore intensities are set for each type of tidal bores. The freesurface gradients are consistently enlarged in high-curvature section for undular and breaking bores, but have distinct behaviors in low-curvature section. The spatial distributions of tidal bore propagation celerity and flow velocity are compared between concave and convex banks. This work will provide experimental reference for engineering design of beach and seawall protection, erosion reduction and siltation promotion in estuary areas with the existence of tidal bores. 展开更多
关键词 tidal bore curved channel flume experiment propagation celerity bore intensity
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A Dynamic Plunger Lift Model for Shale Gas Wells
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作者 Shiyu Miao Xiao Liu +3 位作者 Xiaoya Feng Haowen Shi Wei Luo Peng Liu 《Fluid Dynamics & Materials Processing》 EI 2023年第7期1735-1751,共17页
At present,the optimization of the plunger mechanism is shale gas wells is mostly based on empirical methods,which lack a relevant rationale and often are not able to deal with the quick variations experienced by the ... At present,the optimization of the plunger mechanism is shale gas wells is mostly based on empirical methods,which lack a relevant rationale and often are not able to deal with the quick variations experienced by the production parameters of shale gas wells in comparison to conventional gas wells.In order to mitigate this issue,in the present work,a model is proposed to loosely couple the dynamics of gas inflow into shale gas wells with the dynamics of the liquid inflow.Starting from the flow law that accounts for the four stages of movement of the plunger,a dynamic model of the plunger lift based on the real wellbore trajectory is introduced.The model is then tested against 5 example wells,and it is shown that the accuracy level is higher than 90%.The well‘switch’,optimized on the basis of simulations based on such a model,is tested through on-site experiments.It is shown that,compared with the original switch configuration,the average production of the sample well can be increased by about 15%. 展开更多
关键词 Shale gas well complex and more complex well bore structure plunger lift loose coupling simulation model
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