Improved Serviceability Criteria for Steel Girder Bridges

Improved Serviceability Criteria for Steel Girder Bridges

Michael G.Barker,Ph.D.,P.E.1;and Karl E.Barth,Ph.D.2

Abstract:Current AASHTO LRFD Bridge Design Speci ?cations Service I de ?ection limits are in place with the purpose to prevent deformation-induced structural damage and psychological user discomfort from excess bridge vibration.Previous research has shown that de-?ection criterion alone is insuf ?cient in controlling excess bridge vibrations and structural deterioration of the concrete deck.Previous research shows that natural frequency criteria better controls excess vibration than de ?ection criteria alone.In addition,previous research shows no sig-ni ?cant correlation between de ?ection and structural deformation of the concrete deck slab.To better control excess bridge vibrations and deformation-induced structural deterioration,two new separate criteria formulations are proposed.The ?rst formulation consists of a natural frequency criteria transformed into de ?ection-type terms familiar to the typical bridge engineer.The second proposed formulation directly con-trols the acting ?exural strain in the concrete deck to control deformation-induced structural damage.The proposed serviceability criteria are applied to a database of 185steel girder bridges.Both the as-built behavior and the design optimized behavior are examined and compared with current AASHTO serviceability criteria.The proposed user comfort and deformation-induced damage serviceability formulations are intended to be incorporated into ongoing Federal Highway Administration and bridge industry long-term bridge performance research where service-ability criteria is an important component.DOI:10.1061/(ASCE)BE.1943-5592.0000402.?2013American Society of Civil Engineers.CE Database subject headings:Girder bridges;De ?ection;Vibration;Serviceability.Author keywords:Bridge de ?ections;Bridge vibrations;Bridge serviceability.

Introduction

De ?ection limits have their origin from the railroad industry and were an attempt to limit bridge vibrations.The 1905American Railroad Association limited the span-to-depth ratio as an indirect method of limiting de ?ections.In the 1930s,the U.S.Bureau of Public Roads performed a study to determine a design method that would limit excess bridge vibration (Barth et al.2002).The study included bridges common for the time period that consisted of wood plank decks with a superstructure of pony and pin connected trusses and simple beam bridges.There were no composite beams and few continuous spans.If the building material was steel,ASTM A7steel was the typical grade.The American Association of State Highway Of ?cials (AASHO)de ?ection limits ?rst appeared in 1941,partially because of the results of the Bureau of Public Roads Study (Fountain and Thunman 1987).

The ASCE (1958)investigated the origins for these service load de ?ection requirements and reported that no clear basis for the limits was found (Barth et al.2002).

The AASHTO LRFD Speci ?cations (2012)details general de-sign principles.Article 2.5.2.6advises that the maximum defor-mation of the bridge should not exceed the (span length)/800for general vehicular bridges and the (span length)/1,000for vehicular bridges with pedestrian traf ?c.The reason for the smaller allow-able de ?ection for pedestrian bridges is that pedestrians are more

sensitive to bridge vibrations than vehicular passengers.AASHTO suggests that the service live load does not exceed the AASHTO truck design loading for determining de ?ections.Live-Load De?ection Studies

A collection of previous studies (Fountain and Thunman 1987;Goodpasture and Goodwin 1971;Nevels and Hixon 1973)in-vestigated the relationship between service deformations and deck deterioration.These studies did not ?nd any signi ?cant correlation.A collection of studies (Walker and Wright 1971;Aramraks 1975;and DeWolf and Kou 1997)investigated bridge vibration behavior.Human response to vibrations and the effects that vibration has on the cracking of the concrete deck were examined.The con-clusions of these studies were that live-load de ?ections alone are insuf ?cient in controlling excessive bridge vibration,and that bridge vibration behavior is in ?uenced more by the natural frequency of the bridge,vehicle speed,and surface roughness.

Humans have two types of response to vibration.The ?rst is physiological,which occurs when frequencies of vibration approach resonance with the natural frequencies of internal organs.These effects can cause physical discomfort.Psychological discomfort generally occurs from unexpected motion,such as a pedestrian on a bridge with a truck approaching.The AISC (2003)details how an activity a person is performing affects psychological discomfort.The typical example is a person sitting in an of ?ce who is going to be more susceptible to vibrations than a person walking on a busy bridge.This is because,in a noisy environment,a person is mentally prepared for vibrations compared with those in a quiet environment (Allen et al.1997).

There is a growing movement in structural engineering to move away from simple length/number ratios for de ?ection serviceability limits.The Ontario Ministry of Transportation and Communications Highway Engineering Division (1983)does not limit de ?ection as a function of only span length,rather the maximum de ?ection is based on the natural frequency of the bridge.The Ontario Ministry of

1

Professor,Civil and Architectural Engineering,Univ.of Wyoming,Laramie,WY 82070(corresponding author).E-mail:Barker@https://www.wendangku.net/doc/40353697.html, 2

Jack H.Samples Professor,Civil and Environmental Engineering,West Virginia Univ,Morgantown,WV 26506.

Note.This manuscript was submitted on February 2,2012;approved on April 18,2012;published online on April 20,2012.Discussion period open until December 1,2013;separate discussions must be submitted for in-dividual papers.This paper is part of the Journal of Bridge Engineering ,Vol.18,No.7,July 1,2013.?ASCE,ISSN 1084-0702/2013/7-673–677/$25.00.

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Transportation and Communications Highway Engineering Division (1983)has three different limit levels:the most conservative is for bridges with heavy pedestrian traf ?c,a middle level for some pe-destrian use,and the most liberal for bridges with no intended pe-destrian use.The Australian Bridge Code (1996)also uses a natural frequency based de ?ection limit (Barth et al.2003).In building design,there is a growing movement away from the traditional length/number serviceability de ?ection limit and toward vibration limits,such as those presented in the AISC Design Guide 11(2003).The AISC Design Guide 11(2003)is a natural frequency-based design to limit excess vibrations in a building structure.The heavy explanatory nature of the AISC Design Guide 11indicates that many engineers are not overly familiar with natural frequencies (Allen et al.1997).Whereas ?nite-element packages and other computer programs can easily compute the modal natural frequencies of a structure,it can be a challenge to properly input the bridge into the model.For these reasons,it is desired to derive a user comfort design check that,although based on natural frequency,uses de ?ection type terms that are well known to the typical bridge engineer.Purpose

This paper presents formulations that directly incorporate vibration serviceability limits to control user comfort directly and directly limit concrete deck strains to control deformation-induced structural deck damage (Staebler 2010).The proposed equations are formu-lated in familiar mechanics terms:the vibration serviceability limit appears like a de ?ection check,and the deck strain limit is simply a ?exure limit.The procedures are derived and applied to a suite of 185bridges.

Bridge Database Suite

This study used a database containing 185steel girder bridges

located throughout the US.The database contains a mix of non-composite,composite only in positive moment region,and com-posite bridges.The database contains 126single-span bridges and 59continuous multispan bridges.All of the bridges successfully meet current AASHTO Service I de ?ection criteria.Table 1shows a summary of bridge properties by span.

User Comfort

To better control excess bridge vibration,the objective is to derive

a user comfort serviceability limit based on the natural frequency of the bridge,but formulated in terms familiar to the typical bridge engineer.The formulation is based on correlating user comfort to the natural frequency and maximum acceleration from a dynamic pluck test.The composite bridge (whether designed composite or not,because it will act composite at service levels)is loaded at the point that incurs maximum de ?ection,the load is removed in-stantaneously,and free vibration is allowed.The response is then correlated to the daily expected de ?ections produced from the fa-tigue truck loading.

Dynamics of the bridge pluck test gives the maximum acceler-ation as

€u ?D e2p f n T2

(1)

where €u 5vertical acceleration,D 5de ?ection of the initial pluck

test,and f n 5natural frequency of the bridge girder.

It is desired for the resulting acceleration to be less than some percentage,a lim ,of the acceleration of gravity.For multispan bridges,Wu (2003)developed correction factors that are applied to the natural frequency of a simple-span bridge

f n ?l 2f ss (2)f ss ?p

2L 2

?????????EI b g w r (3)

l 2?a

I c L max

(4)

where f ss 5natural frequency of a simple span girder,l 5correction factor for Multispans a ,b ,and c from Table 2(Wu 2003),L max 5maximum span length for multispan bridges,w 5weight per unit length of the bridge girder,L 5span length,I b 5transformed short-term composite moment of inertia at the midspan,and E 5modulus of elasticity of steel.

The inequality is rearranged to solve for the maximum allowed fatigue de ?ection,D Allow ,which represents a vibration control limit.The serviceability design limit becomes

D fat #D Allow

(5)D Allow

?

a lim p wL 44EI b

(6)

where D fat 5analytical de ?ection from the AASHTO fatigue truck loading.

The proposed procedure is based on the simpli ?ed pluck test,and thus the natural frequency of the bridge,calibrated to acceptable limiting vibrations.Although the term a is the pluck test accelera-tion,it is not the vertical acceleration experienced by the user.To avoid attaching the magnitude of a to user felt accelerations,a design limit X factor is introduced as the percentage of gravity,a lim ,divided by p 4.The calibration determines appropriate limiting X factors,X lim ,and a is not confused with actual user felt accelerations.The design limit X lim is substituted into the aforementioned allowable de ?ection.

Table 1.Bridge Database Property Summary Number of Spans 1span 2span 3span 4span 5span 6span Number of bridges 126.0020.08.025.0 5.0 1.00Span length range (m) 6.1–62.59.1–51.811.6–51.811–52.713.4–3011.9–25.8Steel strength range (MPa)225–345225–34533–34533–34533–345250L =D range

8.75–42.20

14.3–34.8

16.6–29.6

16.8–33.7

19.0–23.6

20.80–21.10

Table 2.Multispan Coef ?cients for Natural Frequency Spans a b c 2

0.95390.045860.031763or more

0.8785

20.03311

0.03348

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D Allow ?X lim

wL 4l 4EI b

(7)

The resulting serviceability design limit uses the natural frequency to control user comfort;however,it is formulated to appear as a de ?ection limit.The formulation of the aforementioned service-ability criterion is proposed;however,the appropriate value of X lim requires further calibration.This calibration process will involve analyzing existing bridges with recorded acceptable and unac-ceptable bridge vibration behavior.For demonstration purposes,the X lim was correlated to the Ontario Ministry of Transportation and Communications Highway Engineering Division ’s natural fre-quency criteria (Staebler 2010).In this case,there are three values of X lim based on the following levels of intended pedestrian use:little to no intended pedestrian traf ?c,medium pedestrian traf ?c,and heavy pedestrian traf ?c.The correlated values for these demonstration X lim factors are given in Table 3.

To examine the proposed serviceability limit,the suite of bridges is used to back-calculate the as-built X factors associated with the speci ?c bridge dynamic properties.The as-built X factors are cal-culated by manipulating the aforementioned design inequality into an equation for calculating X As -Built

X As -Built ?D fat l 4EI b

4 (8)

For the given bridge suite,the as-built X factors are compared with the three X lim for no pedestrian use,some pedestrian use,and heavy pedestrian use in Fig.1.Any data point above a given X lim line violates that respective proposed formulation.For example,a data point with a value higher than the X lim for some pedestrian use is unsatisfactory for a bridge with some intended pedestrian use.The ratios of the as-built fatigue de ?ection to maximum allowable de ?ection,as per the proposed X lim method,for the bridge suite,are shown in Fig.2.In Fig.2,any data point above the 1.0line is considered unsatisfactory

for bridge vibration for that given X lim .A given bridge structure may be acceptable for a bridge with no intended pedestrian use,but un-acceptable for either some or heavy intended pedestrian use.Fig.2shows,in a more linear sense,which bridges would fail the proposed criteria when correlated to the Ontario Ministry of Transportation and Communications Highway Engineering Division (1983).

Whereas all of the bridges meet the current AASHTO Service I de ?ection criteria,several of them violate the criteria for heavy intended pedestrian use.This shows a possible inadequacy in the current AASHTO de ?ection criteria in controlling user comfort.These bridges are suitable candidates for further study in the future calibration for X lim .

Figs.1and 2illustrate the bridge response with the AASHTO fatigue loading and the as-built conditions.This does not necessarily demonstrate the response when a bridge is at its optimal design limit.Most of the bridges in the database are overdesigned.Thus,the responses of concern are lower than those that would be present with an optimized bridge.The amount of overdesign can be represented by the rating factor.For instance,with a rating factor of 1.50,the bridge can withstand 50%more truck loading before reaching its optimized design limit.

To examine the serviceability response that would occur for an optimized bridge,the loads (and thus the de ?ections)can be in-creased by the rating factor (Staebler 2010).The response will represent the behavior as if the bridge is at the design limit.Fig.3shows the X factors for the optimized bridges versus span length.A data point above a given X lim line indicates that bridge violates that proposed limit.Fig.4shows the ratios of optimized fatigue de ?ections to maximum allowable de ?ections,as per a given X lim value,for the bridge suite.A data point with a value higher than 1is unsatisfactory in performance for that given level of intended pedestrian use.

Figs.3and 4show that several bridges optimized for current AASHTO (2012)Strength I,Service I,and Service II criteria violate the proposed user comfort serviceability criteria.Five of the bridges violate the most liberal criteria,that of no intended pedestrian use.This is a strong indication that current AASHTO Service I criteria may be inadequate in controlling excessive bridge vibrations for particular bridges.This inadequacy is even more pronounced in bridges with heavy intended pedestrian use.A signi ?cant number of bridges in the database violate this most conservative limit when the bridge is optimized for current AASHTO design limit states.

Table 3.X lim for Various Levels of Intended Pedestrian Traf ?c Level of pedestrian traf ?c X lim Little to none 0.01370Some pedestrian 0.00685Heavy

0.00274

Fig.1.X As -Built versus span

length Fig.2.D fatAs -Built =D Allowable versus span length

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Deformation-Induced Structural Deterioration A second perceived objective of the current AASHTO Service I de ?ection limit is to prevent deformation-induced structural de-terioration (deck cracking).However,previous research has found no signi ?cant correlation between de ?ection and deck deterioration (ASCE 1958;Walker and Wright 1971;Goodpasture and Goodwin 1971).To con ?rm this,the optimized pier moment deck strains were calculated for each continuous span bridge in the bridge suite.The lack of signi ?cant correlation between Service I de ?ection and tensile strain in the concrete deck is clearly shown in Fig.5,where deck strains are plotted against de ?ections.This research proposes a direct concrete deck performance check to control deck cracking deterioration.The objective is to limit concrete deck strain directly when subject to the maximum expected moment demand.The maximum expected moment is the negative pier moments in con-tinuous spans using the AASHTO LRFD Service II loading.

Because concrete is going to crack when the strain in the deck is equal to the concrete cracking strain,the following maximum strain limit is proposed:

M SerII

ES Deck

#?lim

(9)

where S deck 5short-term composite transformed section modulus for the top of the concrete deck,and M SerII 5peak negative moment at the pier because of Service II loading.

Fig.6shows the concrete strains,both as-built and optimized versus span length,for the database bridges.Few of the concrete strains in the ?gure are greater than 0.001,a reasonable limit for concrete cracking (Staebler 2010).Furthermore,there is not a large difference in behavior between the optimized and as-built bridges.Although the formulation shown in Eq.(9)is proposed,the ?nal appropriate value of ?lim needs to be calibrated in future research with consideration for the proposed Service II loading.

Conclusions

Current AASHTO (2012)procedures offer serviceability criteria that are perceived to control user comfort and deformation-induced structural deterioration (deck cracking).However,studies show that current AASHTO serviceability criteria may be insuf ?cient in controlling excess bridge vibrations (user comfort)and deck cracking (structural deterioration).The results of this research ef-fort reinforce the conclusions of previous studies.To better

control

Fig.3.X Optimized versus span

length

Fig.4.D fatOpt =D Allowable versus span

length

Fig.5.Service II tensile strain in concrete deck versus Service I de ?

ection

Fig.6.Strain versus span length

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bridge vibrations and deformation-induced structural damage,the following two formulations are https://www.wendangku.net/doc/40353697.html,er Comfort

The proposed formulation for serviceability criteria to control excess bridge vibration is

D fat #D Allow

(10)

D Allow ?X lim

wL 4l 4EI b

(11)

where D Allow 5maximum allowable de ?ection,D fat 5de ?ection from the AASHTO fatigue truck loading,w 5weight per unit length of the bridge girder,L 5span length,I b 5transformed short-term composite moment of inertia at the midspan,E 5modulus of elasticity of steel,l 5natural frequency correction factor for multispan bridges (Wu 2003),and X lim varies depending on the level of pedestrian use (no pedestrian use,some pedestrian use,and heavy pedestrian use).

The ability to successfully relate X lim to existing bridge codes based on natural frequency show that the proposed user comfort serviceability limit formulation is a viable method that warrants future research.The parameter X lim for differing levels of pedestrian use needs additional calibration.X lim follows anticipated behavior of bridges and natural frequencies.The proposed limit successfully transforms a natural frequency-based limit into a de ?ection term familiar to bridge engineers.

This research proposes that the expected daily load be used for controlling user comfort,because user comfort is a daily occurrence.Furthermore,a violation of user comfort by a rare maximum expected load is unlikely to cause a major concern for the bridge user.The lower occurrence frequency of these maximum expected loads is low enough to not warrant reducing bridge economy by designing for more conservative loadings.The fatigue truck-load de ?ection is,therefore,proposed because it represents the expected daily load.Deformation-Induced Structural Damage

The proposed formulation for serviceability criteria to control deformation-induced deck cracking at the piers is

M SerII

E conc S Deck

#?lim

(12)

where S deck 5section modulus for the top of the concrete deck,short-term composite,E conc 5modulus of elasticity of concrete,M SerII 5peak negative moment at the pier because of Service II loading,and ?lim 5limiting concrete tensile strain.

Preventing deck deterioration requires more than simply limiting the strain in the concrete deck under service level loads.There are many other factors that must be taken into account,such as allowing for thermal expansion,taking into account beam-deck interactions,proper drainage,and curing.However,the proposed strain limit is an appropriate method to control deck deterioration that may occur directly from traf ?c loads.?lim requires additional research for full calibration.Deformation-induced structural deterioration is a maximum load-type occurrence.As such,the moment used to determine the direct ?exural strain in the concrete deck is from the maximum expected serviceability load.Because the Service II loading represents the largest expected load,the Service II moment is proposed for calculating ?exural strain in the concrete deck.

Calibration and Implementation of Proposed Serviceability Criteria

The proposed user comfort and deformation-induced damage ser-viceability criteria have been applied to a suite of 185bridges as shown herein.The criteria represent an advancement in service-ability of steel girder bridges in that it separately de ?nes,analyzes,and limits bridge response to control user comfort and deformation-induced structural damage.The criteria are formulated in terms and behaviors familiar to bridge engineers.Although the proposed form has been developed and applied to the suite of bridges,the criteria design limits used for evaluation were assumed and derived from other sources not necessarily applicable to bridges in the U.S.The proposed criteria are intended to be further developed,calibrated,veri ?ed,and implemented in ongoing Federal Highway Adminis-tration research on long-term bridge performance.

Acknowledgments

Special thanks to Mark Jablin and Jay Puckett from Bridge Tech,Laramie,WY,for the analysis of the bridge suite.

References

AASHTO.(2012).LRFD bridge design speci ?cations ,6th Ed.,AASHTO,Washington,DC.

AISC.(2003).AISC design guide 11:Floor vibrations due to human Ac-tivity ,AISC,Chicago.

Allen,D.E.,Murray,T.M.,and Ungar,E.E.(1997).Design guide 11?oor vibrations due to human activity ,AISC and Canadian Institute of Steel Construction,Chicago.

Aramraks,T.(1975).“Highway bridge vibration studies.”Rep.No.JHRP-75-2,Joint Highway Research Project,Indiana State Highway Com-mission,Purdue Univ.,West Lafayette,IN.

ASCE.(1958).“De ?ection limitation of a bridge.”J.Struct.Div.,84(Rep.No.ST3).

Australian Bridge Design Code.(1996).Section six —Code,steel and composite construction ,Austroads,Haymarket,Australia.

Barth,K.,Bergman,A.,and Roeder,C.(2002).“Improved live load de-?ection criteria for steel bridges.”Report Prepared for National Co-operative Highway Research Program ,Univ.of Washington,Seattle.Barth,K.E.,Roeder,C.W.,Christopher,R.A.,and Wu,H.(2003).“Evaluation of live load de ?ection criteria for I-shaped steel bridge design girders.”High Performance Materials in Bridges,Proc.of the International Conf.,ASCE,Reston,VA,193–208.

DeWolf,J.T.,and Kou,J.W.(1997).“Vibrational behavior of continuous span highway bridge-in ?uence variables.”J.Struct.Eng ,123(3),333–344.Fountain,R.S.,and Thunman,C.E.(1987).“De ?ection criteria for steel highway bridges.”Proc.,National Eng.Conf.,AISC,Chicago,20-1–20-12.Goodpasture,D.W.,and Goodwin,W.A.(1971).“Final report on the evaluation of bridge vibration as related to bridge deck performance.”Tennessee Dept.of Transportation,Univ.of Tennessee,Knoxville,TN.Nevels,J.B.,and Hixon,D.C.(1973).“A study to determine the causes of bridge deck deterioration.”Final Report Prepared for State of Oklahoma Department of Highways ,State of Oklahoma Dept.of Highways,Oklahoma City.

Ontario Ministry of Transportation and Communications Highway Engi-neering Division.(1983).Ontario highway bridge design code ,2nd Ed.,Toronto.

Staebler,J.(2010).“Alternative steel serviceability limits to control excess bridge vibrations and structural deterioration.”M.S.thesis,Civil Engineering,Univ.of Wyoming,Laramie,WY.

Walker,W.H.,and Wright,R.N.(1971).“Criteria for the de ?ection of steel bridges.”Bulletin for the American Iron and Steel Institute ,AISC,Washington,DC.

Wu,H.(2003).“In ?uence of live-load de ?ections on superstructure perfor-mance of slab on steel stringer bridges.”Ph.D.thesis,College of Engi-neering and Mineral Resources,Univ.of West Virginia,Morgantown,WV.

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Hibernate中Criteria的完整用法

QBE (Query By Example) Criteria cri = session.createCriteria(Student.class); cri.add(Example.create(s)); //s是一个Student对象 list cri.list(); 实质：创建一个模版，比如我有一个表serial有一个giftortoy字段，我设置serial.setgifttoy("2"), 则这个表中的所有的giftortoy为2的数据都会出来 2: QBC (Query By Criteria) 主要有Criteria,Criterion,Oder,Restrictions类组成 session = this.getSession(); Criteria cri = session.createCriteria(JdItemSerialnumber.class); Criterion cron = Restrictions.like("customer",name); cri.add(cron); list = cri.list(); ============================== 比较运算符 HQL运算符QBC运算符含义 = Restrictions.eq() 等于 <> Restrictions.not(Exprission.eq()) 不等于 > Restrictions.gt() 大于 >= Restrictions.ge() 大于等于 < Restrictions.lt() 小于 <= Restrictions.le() 小于等于 is null Restrictions.isnull() 等于空值 is not null Restrictions.isNotNull() 非空值 like Restrictions.like() 字符串模式匹配 and Restrictions.and() 逻辑与 and Restrictions.conjunction() 逻辑与 or Restrictions.or() 逻辑或 or Restrictions.disjunction() 逻辑或 not Restrictions.not() 逻辑非 in(列表) Restrictions.in() 等于列表中的某一个值 ont in(列表) Restrictions.not(Restrictions.in())不等于列表中任意一个值 between x and y Restrictions.between() 闭区间xy中的任意值 not between x and y Restrictions.not(Restrictions..between()) 小于值X或者大于值y 3: HQL String hql = "select https://www.wendangku.net/doc/40353697.html, ,avg(s.age) from Student s group by https://www.wendangku.net/doc/40353697.html,"; Query query = session.createQuery(hql); list = query.list(); .... 4: 本地SQL查询 session = sessionFactory.openSession(); tran = session.beginTransaction();

presentation evaluation criteria

Professional Studies Presentation Evaluation Criteria The numbers in the top of the boxes are points in a continuum. For example, you can assign 20 points for Organization. As long as you do not give more points than suggested in the leftmost box, the score will range between 0 and 100 when you add up the numbers. Organization (20%) 20 Consistently clear, concise, well organized. Points were easy to follow because of the organization. Transitions between sections smooth and coordinated. 15Usually clear, concise, well organized. Most of the presentation was easy to follow. Transitions between sections usually coordinated. 10Not always clear or concise. Organization was adequate, but weak. Occasionally wandered and was sometimes difficult to follow. Transitions between sections weak. 5Often unclear and disorganized, rambled too much. The presentation was confusing and difficult to follow. Transitions between sections awkward. Topic Knowledge (20%) 20Displayed an excellent grasp of the material. Demonstrated excellent mastery of content, application and implications. Excellent research depth. 15Displayed a general grasp of the material. Demonstrated good mastery of content, application and implications. Good research depth. 10Displayed some grasp of the material. Demonstrated adequate mastery of content, application and implications. Research not very deep. 5Displayed a poor grasp of the material. Demonstrated a superficial handling of content, application and implications. Little depth of research. Creativity (10%) 10Very creative and original. Imaginative design and use of materials. Novel handouts, visual aids, or methods. 8 Exhibited some originality and creativity. 5 Routine treatment, minimal thought given to originality or creativity. 3Lacked creativity. Very ordinary and mundane. Visual Aids (15%) 15Simple, clear, easy to interpret, easy to read. Well coordinated with content, well designed, used very effectively. Excellent example of how to prepare and use good visual aids 11Usually clear, easy to interpret, easy to read. Generally well coordinated with content, design was okay, generally used effectively. Demonstrated some understanding of how to use visual aids. 8 Marginally acceptable, too complex, crowded, difficult to read or interpret. Adequate coordination with content. Used only adequately. Showed little understanding of how to prepare and use visual aids. 4Poor quality visual aids (or none), hard to read, technically inaccurate, poorly constructed. Poor coordination with content. Used poorly. The presenter did not seem to know how to prepare or use visual aids effectively. Summary (15%) 15Clear, concise, major points emphasized, clear recommendations, strong conclusion or call for action. 11Referred to main points, recommendations weak or missing, weak conclusion or call for action. 8Vague mention of major points, no recommendations, weak conclusion, weak or no call for action. 4No summary, no recommendations, no conclusions, no call for action. Stage Presence (20%) 20 Excellent stage presence. Confident, used notes well, at ease, excellent gestures, good audience attention, good eye contact. 15Good stage presence. Fairly confident, used notes fairly well, good gestures, acceptable audience attention and eye contact. 10 Adequate stage presence. Read parts, fumbled with notes, several distracting mannerisms, minimal gestures, minimal eye contact, too many um=s. 5Poor stage presence. Unprepared, awkward, shuffled papers, poor eye contact, lots of um=s, turned from audience to read overheads, shuffled feet, fidgeted. Poor gestures. TOTAL POINTS COMMENTS:

Design Criteria

Design Criteria Building optimization must be followed by design criteria; these design criteria are given by the corresponding code. With the aim to determine the optimization criteria I personally have chosen the IBC 2013 Code with the corresponding related codes, such as ACI 318 and ASCE-7, concrete and load codes. Firstly we should determine the basic requirements for a high-rise building with shear wall structure and deep foundation as a foundation system, being this kind of building the objective of the study in situ. ?Building use and occupancy: (CHAPTER 3)Residential group R-2, residential occupancies containing sleeping units or more than two dwelling units where the occupants are primarily permanent in nature, including: Apartment houses, Boarding houses (non-transient), Convents, Dormitories, Fraternities and sororities, Hotels (non-transient), I Live/work units, Monasteries, Motels (non-transient), Vacation timeshare properties. ?Requirements based on occupancy:(CHAPTER 4) 1. For buildings not greater than 420 feet (128 m) in building height, the fire-resistance rating of the building elements in Type IA construction shall be permitted to be reduced to the minimum fire-resistance ratings for the building elements in Type IB. 2. In other than Group F-1, M and S-1 occupancies, the fire-resistance rating of the building elements in Type IB construction shall be permitted to be reduced to the fire-resistance ratings in Type IIA. 3. Bond strength:

criteria范文

criteria范文 我抄袭作业的原因是因为我想早点写完作业早点玩，谁都想玩，但是假如为了玩就抄 作业的话太不值了，现在玩只能玩一会，假如学习不好，以后找不着工作，没钱吃饭，还 谈的上玩吗我抄袭作业抱有一种作业是做给老师看的这种想法，其实根本不是，我们不 做作业，老师就不用批改作业，反而更轻松。所以，作业是为自己做的，我这么想辜负了 老师的一片好心，所以，我向老师表现出深深地歉意! One point is clear that different issues have different objective criteria. For example, criteria of price talking will include factors of cost, market situation, depreciation, price competition and other necessary factors. In other negotiations, exper ts’ opinions, international conventions and norms and legal documents will all serve as objective criteria. 为解决本人衣服无人洗，饭菜无人做，花钱无节制，生活无压力的现状，本人新引进 一招商项目，将于2020年02月20(26)日17时30分举行盛大的庆典活动，请亲朋好友准时参加! In the Sino—US negotiation on China’s accession into WTO, the two parties disputed over China’s developing country status. US took the position that China should be treated as a developed country. To back US stance, American negotiators cited China’s growing exports and large foreign reserve holdings. They a rgued that in developing countries China’s sophisticated technology in launching and retrieving satellites had no parallel. One American negotiator even compared the situation in China with that in India and some African countries. He said when he opened the door of a family in a poorest area randomly chosen by the Chinese government and asked the people if they had their breakfast, he was told they did, and he went on asking if lunch and supper were guaranteed, the answer was yes. However he had a very different story in some African countries and even in some areas in India. People there had little food for breakfast, not mention lunch and supper. The two countries insisted on their own standards and it was hard to bridge the discrepancy. Here the focus is which criterion to apply to for resolving the dispute. In fact there is a ready criterion provided by the World Bank, which is measured by per capita GNP. According to the World Bank’s standard, countries whose per capita GNP below $785 (1996) are the poorest countries. China’s per capita GNP in 1997 was $750, which is among the poorest countries. 甲方聘用乙方的月薪为_____元(含养老、医疗、住房公积金)。试用期满后，并经考 核合格，可根据平等协商的原则，签订正式劳动合同。

条件类Criteria的用法

复合查询主要是处理，具有关联关系的两个实体怎样进行关联查询，比如User 实体对象与Addres实体对象具有一对多的关联关系，我们可以如下构造 符合查询： Criteria criteria=session.createCriteria(User.class); Criteria addcriteria=criteria.createCriteria(“addresses”);(1) addcriteria.add(Express.like(“address”,”%tianjin%”)); List list=criteria.list(); for(int i=0;i User user=(User)list.get(i); System.out.println(user.getName()+”\n”); Set addresses=user.getAddresses(); Iterator it=addresses.iterator(); while(it.hasNext(){ Address address=(Address)it.next(); Syste m.out.println(address.getAddress()+”\n”); } } 当执行到了（1）处时，表明要针对User对象的addresses属性添加新的查询条件，因此当执行criteria.list()时，Hibernate会生成类似如下的SQL语句： Select * from user inner join address on user.id=address.id where address.address like …%shanghai%?; 正如我们所见，我们可以通过向Criteria中添加保存关联对象的集合属性（addresses属性保存与User对象相关联的Address对象），来构造复合查询，在数据库一端是通过内连接查询来实现。 Hibernate QBC查询 QBC查询：

criteria使用总结(目前只会单表)

Criteria的使用总结 1、目前只遇到用于单表查询（多表查询期待中。。。） public Integer getqueryTamArchivesCount(String content, String fileNumber, String fileType, Date beginDate,Date endDate){ DetachedCriteria criteria = DetachedCriteria .forClass(TamArch.class); if (content != null && content.trim().length() > 0) { //模糊匹配 criteria.add(Restrictions.like("subject", "%" + content + "%")); } if (fileNumber != null && fileNumber.trim().length() > 0) { //相等 criteria.add(Restrictions.eq("archivesNo", fileNumber)); } if ("1".equals(fileType)) { //或者 criteria.add(Restrictions.or(Restrictions.eq("archivesStatus", "1"), Restrictions.eq("archivesStatus", "2"))); }else if("2".equals(fileType)){ criteria.add(Restrictions.eq("archivesStatus", "99")); } if(beginDate!=null&&endDate!=null){ //两者之间 criteria.add(Restrictions.between("issueDate",beginDate,endDate)); } //按日期降序排列 criteria.addOrder(Order.desc("inputDate")); return archDao.getRowCount(criteria) ; } 注意： ①对于日期有点bug，如果查询的日期为空，则查询不到数据。貌似日期为必填。 ②对于Restrictions.or：只能处理2种的情况 ③ //处理或情况（archivesStatus为2、3、99） criteria.add(Restrictions.in("archivesStatus", new Object[]{"2","3","99"}));

Criteria的几种查询方法使用

Criteria的几种查询方法使用 QBC常用限定方法 Restrictions.eq --> equal,等于. Restrictions.allEq --> 参数为Map对象,使用key/value进行多个等于的比对,相当于多个Restrictions.eq的效果 Restrictions.gt --> great-than > 大于 Restrictions.ge --> great-equal >= 大于等于 Restrictions.lt --> less-than, < 小于 Restrictions.le --> less-equal <= 小于等于 Restrictions.between --> 对应SQL的between子句 Restrictions.like --> 对应SQL的LIKE子句 Restrictions.in --> 对应SQL的in子句 Restrictions.and --> and 关系 Restrictions.or --> or 关系 Restrictions.isNull --> 判断属性是否为空,为空则返回true Restrictions.isNotNull --> 与isNull相反 Restrictions.sqlRestriction --> SQL限定的查询 Order.asc --> 根据传入的字段进行升序排序 Order.desc --> 根据传入的字段进行降序排序 MacthMode.EXACT :字符串精确匹配。相当于like …value? MathMode.ANYWHERE:字符串在中间匹配.相当于like …%value%? MathMode.START:字符串在最前端匹配位置.相当于:like …value%? MatchMode.END:字符串在最后端匹配.相当于:like …%value? 1.查询年龄在20-30之间的所有学生对象。 List list = session.createCriteria(Student.class) .add(Restrictions.between(“amout”,new BigDecimal(1),new BigDec imal(10)).list(); 2.查询S tudent名字开头有t的所有Student: List list = sesison.createCriteria(Student.class) .add(Restrictions.like(“name”,”t%”)).list(); 3.或者使用另一种查询Student名字开头有t的所有Student: List list = sesison.createCriteria(Student.class)

深入浅出Hibernate学习笔记 Criteria Query

本文是对深入浅出Hibernate学习做的学习笔记，是个人在对深入浅出Hibernate学习中的一点认识和看法，下边是具体的内容。 本文是对深入浅出Hibernate学习做的学习笔记，是个人在对深入浅出Hibernate学习中的一点认识和看法，下边是具体的内容。 Criteria Query通过面向对象的设计，将数据查询条件封装为一个对象。简单来说，Criteria Query可以看作是传统SQL的对象化表示，如： 1.Criteria criteria=session.createCriteria(TUser.class); 2.criteria.add(Expression.eq("name","Erica")); 3.criteria.add(Expression.eq("sex",new Integer(1)); 这里的criteria实例本质上是对SQL“select * from t_user where name='Erica' and sex=1”的封装。Hibernate在运行期会根据Criteria中指定的查询条件生成相应的SQL语句。 Criteria查询表达式：Criteria本身只是一个容器，具体的查询条件要通过Criteria.add方法添加到Criteria实例中。 方法描述：Expression.eq 对应SQL “field=value”表达式 如：Expression.eq("name","Erica") 4.Expression.allEq 参数为一个Map对象，其中包含了多个属性-值对应关系。相当于多个 Expression.eq关系的叠加 5.Expression.gt 对应SQL“field>value”表达式 6.Expression.ge 对应SQL“field>=v alue”表达式 7.Expression.lt 对应SQL“fieldfield” 14.Expression.gtProperty 用于比较两个属性之间的值，对应SQL“field>=field” 15.Expression.ltProperty 用于比较两个属性之间的值，对应SQL"field

Hibernate中Criteria的完整用法

最近在项目中使用Spring 和Hibernate 进行开发，有感于Criteria 比较好用，在查询方法设计上可以灵活的根据Criteria 的特点来方便地进行查询条件的组装。现在对Hibernate的Criteria 的用法进行总结： Hibernate 设计了CriteriaSpecification 作为Criteria 的父接口，下面提供了Criteria和DetachedCriteria 。 Criteria 和DetachedCriteria 的主要区别在于创建的形式不一样，Criteria 是在线的，所以它是由Hibernate Session 进行创建的；而DetachedCriteria 是离线的，创建时无需 Session，DetachedCriteria 提供了 2 个静态方法forClass(Class) 或forEntityName(Name) 进行DetachedCriteria 实例的创建。Spring 的框架提供了getHibernateTemplate ().findByCriteria(detachedCriteria) 方法可以很方便地根据DetachedCriteria 来返回查询结 果。 Criteria 和DetachedCriteria 均可使用Criterion 和Projection 设置查询条件。可以设 置FetchMode( 联合查询抓取的模式) ，设置排序方式。对于Criteria 还可以设置FlushModel （冲刷Session 的方式）和LockMode （数据库锁模式）。 下面对Criterion 和Projection 进行详细说明。 Criterion 是Criteria 的查询条件。Criteria 提供了add(Criterion criterion) 方法来 添加查询条件。

Criteria用法详解

hibernate:Hibernate中Criteria的完整使用方法 疯狂代码 https://www.wendangku.net/doc/40353697.html,/ ?:http:/https://www.wendangku.net/doc/40353697.html,/Java/Article58225.html 最近在项目中使用 Spring 和 Hibernate 进行开发有感于 Criteria 比较好用在查询思路方法设计上可以灵活根据 Criteria 特点来方便地进行查询条件组装现在对 HibernateCriteria 使用方法进行整理总结: Hibernate 设计了 CriteriaSpecication 作为 Criteria 父接口下面提供了 Criteria和DetachedCriteria Criteria 和 DetachedCriteria 主要区别在于创建形式不样 Criteria 是在线所以它是由 Hibernate Session 进行创建；而 DetachedCriteria 是离线创建时无需SessionDetachedCriteria 提供了 2 个静态思路方法forClass(Class) 或 forEntityName(Name) 进行DetachedCriteria 例子创建 Spring 框架提供了getHibernateTemplate.findByCriteria(detachedCriteria) 思路方法可以很方便地根据DetachedCriteria 来返回查询结果 Criteria 和 DetachedCriteria 均可使用 Criterion 和 Projection 设置查询条件可以设置 FetchMode( 联合查询抓取模式 ) 设置排序方式对于 Criteria 还可以设置 FlushModel(冲刷 Session 方式)和 LockMode (数据库锁模式) 下面对 Criterion 和 Projection 进行详细介绍说明 Criterion 是 Criteria 查询条件Criteria 提供了 add(Criterion criterion) 思路方法来添加查询条件 Criterion 接口主要实现包括: Example 、 Junction 和 SimpleExpression 而 Junction 实际使用是它两个子类 conjunction 和 disjunction 分别是使用 AND 和 OR 操作符进行来联结查询条件集合 Criterion 例子可以通过 Restrictions 工具类来创建Restrictions 提供了大量静态思路方法如 eq (等于)、ge (大于等于)、 between 等来思路方法创建 Criterion 查询条件 (SimpleExpression 例子)除此的外Restrictions 还提供了思路方法来创建 conjunction 和 disjunction 例子通过往该例子 add(Criteria) 思路方法来增加查询条件形成个查询条件集合 至于 Example 创建有所区别 Example 本身提供了个静态思路方法 create(Object entity) 即根据个对象(实际使用中般是映射到数据库对象)来创建然后可以设置些过滤条件: Example exampleUser =Example.create(u) .ignoreCase // 忽略大小写

CriteriaType【_or、子查询】的使用

CriteriaType _or 的使用 生成的语句： select * from (select this_.ID as ID13_0_, this_.USER_NAME as USER2_13_0_, this_.USER_ID as USER3_13_0_, this_.ORG_NAME as ORG4_13_0_, this_.ORG_ID as ORG5_13_0_, this_.DEPT_NAME as DEPT6_13_0_, this_.DEPT_ID as DEPT7_13_0_,

this_.USER_TITLE as USER8_13_0_, this_.APPRAISER_NAME as APPRAISER9_13_0_, this_.APPRAISER_ID as APPRAISER10_13_0_, this_.APPRAISER_TITLE as APPRAISER11_13_0_, this_.APPRAISER_MIND as APPRAISER12_13_0_, this_.REVIEW_DATE as REVIEW13_13_0_, this_.REVIEW_STATUS as REVIEW14_13_0_, this_.YEAR as YEAR13_0_, this_.BEGIN_DATE as BEGIN16_13_0_, this_.END_DATE as END17_13_0_, this_.CREATE_DATE as CREATE18_13_0_, this_.SIGN_DATE as SIGN19_13_0_, this_.SIGN_STATUS as SIGN20_13_0_, this_.POSITION_DESC as POSITION21_13_0_, this_.SCORE as SCORE13_0_, this_.CONTRACT_TYPE as CONTRACT23_13_0_, this_.DEL_FLAG as DEL24_13_0_ from PERF_PA_APRL_CONTRACT this_ where ((this_.ID in (select this0__.ID from PERF_PA_APRL_CONTRACT this0__ where this0__.USER_ID = ?) or this_.ID in (select this0__.ID from PERF_PA_APRL_CONTRACT this0__ where this0__.APPRAISER_ID = ?)) and this_.DEL_FLAG = ?)) where rownum <= ?

criteria的一些示例语句或方法

Criteria的一些语句范例（方法） 一、Criteria的一些基本查询 Criteria有一个方法add(“限定条件”)，这个方法可以添加限定条件，好得到自己应该要的查询结果；例如：有两个实体类，student和teacher已经有一个Criteria的关于Student 类的实例Criteria crit = session.createCriteria(Student.class)； 1）在一个班级中要查询姓“王”的学生都有谁，就可以这样:List list = crit.add(Restrictions.like(“name”,”王%”)).list(); 2）查询年龄在17-20之间的学生：List list = crit.add(Restrictions.between(“age”,new Integer(17),new Integer(20))).list(); 3）查询没有手机号码的学生：List list = crit.add(Restrictions.isNull(tel)).list(); 4）查询90后的学生：List list = crit.add(Restrictions.ge(new Date(1990-01-01)).list(); 5）查询考试分数在前十名的学生（可用于分页查询）：List list = crit.addOrder(Order.desc(“grades”)).setFirstResult(0).setMaxResult(10).list(); 6）查询学生小明的个人信息：crit.add(Restriction.eq(“name”,”小明”)).list().iterator().next(); 7）查询小明的化学教师的信息：crit.add(Restricrions.eq(“name”,”小明”)).createCriteria(“teacher_id”).add(Restrictions.equ(“subject”,”化 学”)).list().iterator().next(); 8）以上都是先创建session根据session得到Criteria的实体对象（即在线查询），下面来看看离线查询，离线查询用的是DetachedCriteria类，DetachedCriteria类使你 在一个session范围之外创建一个查询，并且可以使用任意的Session来执行它。 下面写还按照上面的条件，写一个例子吧： DetachedCriteria query = DetachedCriteria.forClass(Student.class) .add( Property.forName("name").eq("小明") ); Session session = Configuration().configure().buildSessionFactory().openSession; Transaction txn = session.beginTransaction(); List results = query.getExecutableCriteria(session).setMaxResults(100).list(); https://www.wendangku.net/doc/40353697.html,mit(); session.close(); 二、常用的一些基本的限定方法 Restrictions.eq --> equal,等于. Restrictions.allEq -->参数为Map对象,使用key/value进行多个等于的比对,相当于多个Restrictions.eq的效果 Restrictions.gt --> great-than >大于 Restrictions.ge --> great-equal >= 大于等于 Restrictions.lt --> less-than, <小于 Restrictions.le --> less-equal <= 小于等于 Restrictions.between -->对应SQL的between子句 Restrictions.like -->对应SQL的LIKE子句 Restrictions.in -->对应SQL的in子句 Restrictions.and --> and 关系