海洋生物学-圣诞节英语资料

ROADGUARD

BARRIER SYSTEM
The roadguard barrier, 6 feet long, 3.5 feet high, 2 feet wide at base, with its
patented design, is the only barrier of its type that self locks without the need for
additional assistance.
No barrier, other than the roadguard barrier, can self-lock without the need of
additional apparatus, such as a cable, strap, rod or coupler.
In addition, the roadguard barrier, because of its unique patented design allows
for curved configurations of up to 15 degrees at each barrier connection, in either
direction, while remaining locked to the adjacent barrier. No other barrier can
make that claim!
Also, the roadguard barrier is designed for the addition of signs screens and
flashers because of the built in slots for such devises and is easier to maneuver
because of its weight and two carrying slots contained in each barrier.
The patented interior design of the roadguard barrier prevents bulging and
keeps its side’s straight and trim while maintaining a weight of only 125 lbs.
Empty but a secure 1675 lbs.
The roadguard corner connector barrier is designed for use with the roadguard
barrier as a connecting barrier unit to allow for either left or right angle turns, or
both simultaneously, of between 75 to 105 degrees while locking together all
connecting barriers. In addition, the corner connector barrier allows for the
initial roadguard barrier line to continue after connecting barrier line extensions
to the left andor the right.
Lightweight and easy to handle, the roadguard corner connector barrier is 2
feet in length and width and 3.5 feet in height, designed to correspond with the
roadguard barrier.
Directly beneath the filling hole of the roadguard corner connector barrier is a
pin extending upward internally from the bottom of the barrier to secure firmly a

pole or pipe that can be inserted downward through the filling hole. Said pole
or pipe can be used to attach signage, privacy screens or security panels that
extend above the barrier line height.
The roadguard highway assembly is a reinforcement system for highway
barriers that distribute and transfer forces that may occur upon impact of a
vehicle so that the overall highway barrier system will have greater strength and
integrity. The roadguard highway assembly system meets all NCHRP 350, Test
Level 3 Truck and Car Crash Test Specifications, and is approved by the FHWA
for use on highway construction projects where the posted vehicle speed in a
work zone can be as high as 62-mph100kph.
The roadguard highway assembly is a fabricated steel assembly designed to
easily mount to the roadguard barriers. This ASSEMBLY provides two distinct
functions: Providing a strong and resilient outer surface to resist the wheel and
bumper of a striking vehicle, and to link the barriers more securely to each other
and create a very robust linear system such that the force of a striking vehicle
will be distributed over many barriers, minimizing the lateral movement at the
point of impact.
The roadguard security panel is used for perimeter security, safety, crowd
control and general site protection. These 6’ x 4’ chain link fence panel units
install firmly on a roadguard barrier to give a stable 8 foot high continuous,
unbroken protective fence for all security and safety needs. Optional solid
material, screen, or interwoven chain link panels are available.
Our study area lies in the north of modern delta of the Huanghe River and it
was formed by the river way of Diaokou in Huanghe River has
the largest content of silt and may transport about 10.6Gta silt into the Bohai sea.
The sub-delta was built quickly under the supply of abundant sediments. The
rapid accumulation in the delta always makes the river course to be diverted
frequently. The abandoned delta would be eroded and retreated rapidly after

diversion because the lack of supply. The gradient of the coastal slope in the
delta is very gentle, the water depth is only 10m in the place about 10km apart
from the coastal bank. A few of kilometers-wide tidal flat would be exposed
during ebb tide that makes us work on the tidal flat conveniently. The sediments
on the tidal flat are mainly composed of fine sands, silt and clay.
With the development of economic construction, various kinds of
modernized traffic facility, is it pay to set up such as expressway , city, overpass
function blown strengthen day by day in communications and transportation, the
development of and the communications and transportation has caused the rapid
rising of the traffic accident, traffic Safe and own through becoming a great
world difficult problem
The rigidity guardrail is offended the guardrail form not basically out of shape by
the automobile, generally point the concept of adopting appearance
guardrail of modes in Chinese operatic music of concrete wall of concrete
guardrail , through the different sides of slope of appearance mainly, make the
automobile moderate , it is high to climb, change direction, last making not
colliding kinds of guardrail angle smaller than 100 car not medium-sized making
a change effective to, make automobile receive lighter damage, as angle of
colliding, collide when relatively heavy speed having, the automobile damages
seriously.
According to rigidity with can divide into flexible guardrail , semi-rigid
guardrail and rigidity guardrail safe form of guardrail. 1)The flexible guardrail
generally points the cable guardrail , is one kind with structure that fixes of many
roots on the pillar of cable of exerting prestressing force, totally relying on the
stress of drawing of the cable to resist the vehicle and collide, the form is
beautiful , not oppressing the sense while going, but the sight leads worse, the
fabrication cost is relatively high, do not generally use. 2)The semi-rigid
guardrail generally points the roof beam type guardrail , is a kind of roof beam

type structure fixed with the pillar , depend on the guardrail crooked and out of
shape and a pulling force resist the collision of the vehicle. There are a lot of
kinds of the roof beam type guardrail , use the most extensive one to be the roof
beam guardrail of the wave form . Have certain rigidity and toughness, easy to
change after damaging, can lead the sight , the appearance is beautiful . 3)The
rigidity guardrail generally points the cement concrete wall type guardrail , is a
kind of concrete wall type structure of cement with certain section form , rely on
the automobile to climb high , out of shape and rubing to absorb the energy of
colliding . The guardrail security high, can prevent two accident
effectively, itself difficult to damage, the maintenance cost is low, but have sense
of oppressing to go to the vehicle, it is relatively serious to damage the vehicle.
Security guardrail of expressway should prevent high-speed vehicle that go
from exceed outlet, pass through central authorities is it is it is it to lane , can
lead the driver's sight correctly to intrude upon to take to separate, make the
vehicle get back to normal travel direction, and it is minimum to reduce
malignant degree of the accident to. In a word, high-speed highway safety
guardrail reduce traffic accident and reduce accident malignant effective measure
of degree, but in shouldn't set up place of the guardrail set up the guardrail ,
become the new barrier instead, it is dangerous to increase the accident. So,
should grasp the characteristic of the guardrail to the design of the safe guardrail
first and combine the traffic condition of the expressway, on the premise of
meeting basic function of the guardrail , select the suitable guardrail form for use,
adopt the rational establishment principle.
Because topographical terms , make the investment and technological terms
to restrain from many kinds of factor, way side have barrier unavoidably, to
exceed vehicle of outlet form the potential danger. Way side guardrail set up in
be able to reduce accident serious place of degree only, its design principle is
confirmed according to people's subjective judgement of such factors as class of

highway , volume of traffic , vehicle making up and way side characteristic ,etc..
The most ideal guardrail form is that meet function's needs as well as the
cost is the lowest, and elegant in appearance, and can lead the sight of driving a
vehicle . The cable guardrail is suitable for not having evenly no sinking , snow ,
long straight line , highway section with the special beautiful demand The
concrete guardrail is suitable for very dangerous stepping such highway sections
as the river bridge , cliff ,etc.; Wave form guardrail have heavy suitability,
suitable for all highway section basically, especially small radius curved dish is it
lead highway section of sight to need. Require according to norm and Hunan
Province many pieces of high-speed highway safety guardrail design experience,
the general way side of highway section adopts the roof beam guardrail of the
wave form , the specific very difficult dangerous highway section adopts the
concrete guardrail .
In a situation that the volume of traffic is big, vehicle go at a high speed, is
it cross central authorities separate the situation led to happen, may produce the
serious consequence , so, the central authorities separate the width that bring as
the important basis of setting up guardrail . Anticollision cushion through absorb
vehicle collide energy make vehicle's stopping safely, make the vehicle change
travel direction, avoid the department and take advantage of personnel's
receiving facilities of the serious injury. The anticollision cushion is with low
costs, have very high security performance . It mainly applies from taking in the
middle of not having to bringing and carrying out the transition while having, the
usual friendship channelizing island shunts one, has regular barriers when the
pilosity highway section of the traffic accident. The anticollision cushion has
plastic cushions of systematic anticollision of intermediate layer , fill out such
various forms as the sand plastic barrel anticollision cushion , sand bag ,etc..
Practice has proved , the anticollision cushion is a kind of effective facility , it is
mainly serious degree which reduces the accident, but not reduce the emergence

of the accident. With the rapid development of the expressway of our country,
people have improved a lot understanding of the importance of safe guardrail,
while building the guardrail, should compare from such many aspects as
performance , view and economy ,etc. conscientiously , consider in an all-round
way.
The anticollision guardrail includes the concrete functions of four respects:
1)Prevent vehicle from jump outlet (bridge ) outside, is it bring to separate to
central authorities but speech, is it prevent vehicle from pass through central
authorities is it take but intrude upon correctly the lane to separate to want;
Meanwhile , is it get off vehicle get out under partial toing the breast board , or
break the guardrail to defend; 2)The guardrail should be able to make the vehicle
reply to and stop travel direction frequently 3)While colliding , the damage to
the passenger is the minimum degree: 4)Can lead the sight of the persons who
drive . Can be found out from above-mentioned functions, the guardrail must
have suitable intensity of mechanics and collision in order to keep out the vehicle
of rigidity , prevent the vehicle from crossing outside of outlet (the bridge ):
Meanwhile, rigidity of guardrail can too heavy, can is it injure or lighten the
degree of injuring to protect passenger from better.
Real car full size is it is it offend with actual automobile guardrail is it
imitate a kind of research approach of traffic accident to come to test to bump
into. It can get automobile sport orbit and sport posture in the course of striking ,
such true believable technical parameters as the number value of shock
power ,etc. of deformation and damage characteristic and colliding of the
automobile and guardrail , thus offered the scientific basis for the dependability
of other research approach income results of design and verification of the safe
and reliable guardrail structure. Now, various countries bump into the test of the
real car of the system to regard as the basic prerequisite studied to the guardrail .
Because the way side guardrail itself is a barrier , in a situation that the

condition is permitted, the side guardrail of the way should be set up as much as
possible and far away from the runway. So, the vehicle which deviates from the
runway can perhaps is it answer to sail in the runway again having no accidents
most heavy . Way side object exceed from runway edge sure to after worthing ,
take as the barrier , driver can because reducing speed last position. This distance
is called and leant towards the location horizontally . This distance varies with
speed, must pay attention to guaranteeing the proper transition is designed when
No. link with other structures thing in side guardrails Should also pay attention
to guaranteeing the proper distance between the guardrail and barrier . The
deformation when the guardrail collides is not only an important factor that the
form is chosen, but also an important factor set up . When the barrier especially
protected is a rigidity object, the distance between the guardrail and object
should be large in order to prevent the vehicle from stumbling hindering on the
rigidity object enough. Set up the side guardrail of the way to guaranteeing the
function on the way with safe side is great rationally, but the diversification of
the side guardrail form of the way and influence factor of establishment make the
design of the side guardrail of the way very complicated numerously
Guardrail as superhighway a important one safety devices most one of , can
prevent vehicle from go out highway or intrude upon to to go the lane, have
function of reducing accident losses , guaranteeing the traffic safety, for
improving sense of safety and comfortableness that the department rides
personnel, it is indispensable to improve the economy of highway transportation
and social benefit.
The guardrail is one of the most important safety devices of expressway .
According to the difference which can suck the way, the guardrail is divided into
the following 3 typical forms : Rigidity guardrail , the semi-rigid guardrail and
flexible guardrail . The function of the guardrail is: When the automobile and
guardrail collide , under one's own situation not destroyed , absorb the energy of

colliding partly, and channel the automobile into the runway , guarantee the
automobile does not cross the guardrail and rushes into the relative lane or puts
the bank protection rollingly . So the requisition for guardrail is: Must have
enough intensity and proper rigidity , there should the stronger one that can suck
the characteristic and certain direction ability at the same time.
Obviously, it is different that systematic security with colliding to the
automobile - the semi-rigid guardrail
collides
can is it guide semi- rigid design of guardrail to use for directly either in studying

the size or simple spring - quality - damping system, is it is it study semi-rigid
guardrail for line elastomer semi-rigid designing technique of guardrail wait for
such as anticollision mechanism to come to simplify at the same not
already while studying considered the ball plasticity of the semi-rigid guardrail
moves on the influence of the law to the automobile big and out of shape,
consider geometry form , size and automobile car body structure of automobile
play plasticity to be heavy and out of shape to semi- rigid guardrail heavy
influence out of shape too, have not considered the emergency rate effect of the
material and inertia effect are to the automobile car body structure and large
influence out of shape of semi-rigid guardrail , have not considered the influence
of each and one's own the automobile and semi-rigid guardrail and contact and
friction each other even more. In a word , have not considered any coupling
dynamics phenomenon . Obviously, the essence that the designing technique of
semi- rigid guardrail received like this can not reflect the question , result its
unfavorable to special, great malignant traffic accident prevent and cure
improvement of competence.
We think , two inalienable components in the system that the automobile and
semi-rigid guardrail collide in the automobile bumps into this incident of

semi-rigid guardrail , the mutual coupling of two , influencing each other , form
an organic whole together. While the automobile bumps into the semi-rigid
guardrail , the automobile will keep in touch with the semi- rigid guardrails , and
position and area of contact that are exposed to will change with sport of the
automobile , the contact area changed will produce the contact strength and
frictional force changed changed , under acting on commonly in contact strength
and frictional force changed of changing, semi-rigid guardrail and automobile
car body structure will take place size and whom position change heavy and out
of shape (this kind is big and out of shape and often closely related to the
emergency rate effect of the material and inertia effect), This kind heavy to can
cause new contact while being out of shape (including automobile car body
structure and semi-rigid guardrail are one's own since contact , position and area
are in changing contact each other), then influence the size and direction exposed
to strength and frictional force , influence the sport orbit of the automobile, this
kind feedback function make
strike shape at specific coupling each other.
Now, people collide structure basic principle of dynamics apply other
relevant field, including the study on semi-rigid guardrail , but the restriction that
divided because of the speciality, in design technical research of the semi-rigid
guardrail , have not made breakthrough progress yet. Through the response
characteristic analysis of the human body in the car in the course to colliding, is
it collide course various kinds of sport law that automobile might appear human
body bludgon the influence law responded into to car to find out, confirm in
view of the above that it is most favorable to human body's safe automobile ideal
sport law in the car in the course to collide .
This research and past research are different. Collision security of
automobile study for a large number of research results, author go on a large
number of automobile collide security study too in the past, but the one that

study is all that the automobile stipulating bumps into this kind of special
operating mode of rigidity wall in safety standards of automobiles, purpose that
study to judge mechanics , automobile of structure characteristic suitable and
how improve the automobile structural design, the automobile set up collides
though the model is very complicated, but that serves for the mechanics
characteristic of confirming the automobile structure, it is unnecessary too to
consider target's impact on structural mechanics characteristic of the automobile
struck. And the study on anticollision mechanism of semi-rigid guardrail , is it
consider mechanics characteristic , automobile of structure to want too (whether
former research automobile that set up collide model can for is it serve to study
originally after dealing with), but the more important thing is that will consider
the influence on course of colliding of mechanics characteristic of the semi- rigid
guardrail , and various kinds of coupling phenomena set up through contacting
interfaces between the automobile and semi- rigid guardrail , obviously, such
research and research in the past were different.
The setting-up of the system intact coupling dynamics big system model is
the most key question that
Should consider the semi-rigid guardrail and one's own great phenomena out of
shape of ball plasticity of automobile in the model, and also consider the
semi-rigid guardrail and automobile one's own geometry form and size, consider
such complicated factors as the contact and friction between the automobile and
guardrail ,etc., it is more suitable to adopt the finite element model. For is it
calculate precision and computational efficiency two demand of respect to give
consideration to, to is it is it is it adopt explicit integration form to plan to solve
to ask model, all units adopt some total mark and leading parameter sand and
leak the control technology , in order to improve the computational speed. In
order to make the big system model set up can be used in the research of various
kinds of structure forms of semi-rigid guardrail and design parameters and law

giving consideration to the model more conveniently, plan to set up an
automobile in common use and simplify models, and set up the guardrail model
storehouse made up of several model and characteristic of semi- rigid guardrail
according to the need.
To automobile being structure complicated and a existing one used in
automobile collide automobile that security study calculate model too huge
characteristic, is it is it at the foundation , security of research results , collide to
automobile security commonly used automobile collide model simplify
rationally in studying to collide in existing automobile to plan, set up concise ,
ocular , swift , scientific automobile and simplify models. Simplifying models
can adopt the model of mixing that nodal shell unit and nodal entity's unit eight
four form , use shell unit simulation of the part that may be contacted with the
semi-rigid guardrail on the automobile, other parts adopt entity's unit simulation.
Use automobile - semi-rigid guardrail collide system intact coupling
dynamics model, carry on sensitivity , structure of design parameter analyse ,
study semi-rigid guardrail structure form to collide automobile actual sport
influence law of law in the course at first, automobile law and its the most
unanimous optimum structure form of ideal sport law of real sport by fixing
making . Then to optimum structure form, is it use automobile - semi-rigid
guardrail
law of impact on real sport law of the automobile of design parameter of the
structure, in order to confirm the optimum design parameter.
The experimental number of times that reducible to collide , obtained the
considerable direct economic benefits. For a long time , to semi-rigid design of
guardrail , adopt experience design method , half analyze technology and test
method is it go on to mix all, though can design the feasible guardrail , costly
and time-consuming only according to testing and trying playing, very
unremunerative, and difficult to make the security level of the semi-rigid

guardrail in optimum state. If there is semi-rigid guardrail that designs the new
technology and does guidance, can dispel the potential safety hazard during the
course of designing , reduce and collide the experimental number of times,
reduce once the test of colliding , can economize 100,000-200,000 yuan . In
addition, can optimize the structure of guardrail in the forming and design
parameter, has solved the problem that the traditional method is difficult to
solve .
The new mechanism of the anticollision of semi-rigid guardrail is used in the
design and improvement of the semi-rigid guardrail on the expressway and
special-purpose Class I Highway of automobile mainly, certainly, can apply to
the design and improvement of the semi-rigid guardrail on other highways at all
levels too.
However, impact kinetic energy and its travel speed that the automobile has
are the square of in direct radio, once the high-speed automobile that goes
crosses the traffic accident outside the outlet (the proportion of taking the total
amount of traffic accidents of this kind of accident is about 45%, about 30% on
the expressway on the ordinary arterial highway), the consequence will be more
serious . At this moment , design the furnishing that the unreasonable guardrail
will become the danger , and then influence the effective use of the expressway
and superhighway seriously, can't give full play to the high-speed advantage that
transport safely . Practice indicates , the semi-rigid guardrail is a kind of
guardrail form with very good performance , already used widely worldwide,
because new mechanism semi- rigid to protect design of fence new technology
can make semi-rigid high-speed collision safe performance of guardrail improve
further on the basis of semi-rigid guardrail anticollision, exceed to vehicle outlet
prevention and cure of the traffic accident (accident this kind of the main reason
that cause special , great malignant traffic accident ) have important meanings,
therefore have wide application prospects .

Study on new mechanism of the anticollision of semi-rigid guardrail to
guarantee highway communication transportation system realize at a high speed
transporting basic research of purpose one of safely, it is a subject for research of
crossing in fields multi-disciplinarily, the value of academic research with
importance and prospect of using. It break through professional restriction that
divide in the past, collide the system as a big system of coupling
semi-rigid guardrailproceed from the angle of guaranteeing the safe level is
optimum that the passenger collides in the car , study and collide the ideal sport
law which the automobile should possess in the course, On this basis, through set
up automobile - semi-rigid guardrail collide systematic coupling dynamics
artificial model is it study guardrail anticollision new mechanism to come,
improve the precondition of designing competence of semi-rigid guardrail to the
great break-through of the designing technique of traditional guardrail , have
important meanings to the prevention and cure of the special , great malignant
accident in the traffic accident of the road, so, should launch the study on it , the
improvement of competence in order to guarantee road traffic's security ,
moulding industry's new image of communications and transportation to
establish the technological foundation in a more cost- effective manner .
The rigidity guardrails and semi-rigid guardrails are the important safety
devices on the expressway . Studies have shown rigidity guardrail though out of
shape basically in colliding in accident, but because one's own structure rigidity
is great, not only the ability to absorb energy is low, but also apt to cause two
accidents. The semi-rigid guardrail is a kind of continuous roof beam post type
guardrail structure, because there are certain rigidity and flexibility, have certain
energy absorbability , but lighten the injury to the passenger and vehicle greatly ,
so already widely applied to the highway engineering. The roof beam guardrail
of the wave form is a main form of the semi-rigid guardrail , carry on research of
performance and energy absorbability of safe protection to it, will play a

instructing role to the construction of the expressway of mountain area , will
offer the theoretical foundation for some designs of composite guardrail .
Improve the environmental quality of the underground space and ventilation
result, offer the comfortable environment of going by bus to passenger, offer the
good condition of work to station equipment and staff member , make the
underground environment get effective control. Satisfied when the fire accident
happens in the station or the annex, arrange cigarettes and ventilate effectively,
guarantee passenger's evacuating safely and staff members and equipment
security. When the train blocks the trouble, can maintain passenger's
requirements for fresh air in the carriage .
U.S.A. began the research and use of the guardrail from 1920, on the basis
of theory analysis and simulation experiment, protect and block and collide to
verify the application practice on the experiment and highway through the full
size of real car, have accumulated a large number of materials and abundant
experience. The national traffic research institute of research association of
U.S.A. made the evaluation criterion of the expressway safety devices in 1981,
organized guardrail structure of the expressway and a series of research work of
different safety devices and wrote various kinds of design specifications around
1970 and 1986. Such countries as France , Britain , Germany ,etc. were
beginning the research work of the structure of the guardrail long ago too, set up
and amplify a whole set of experiment facilities and corresponding experiment
rules, have studied the guardrail structure of many kinds from theory and
experiment . The research work of the ones that began in this respect in the fifties
in Japan, and began to use the guardrail regularly in the supernatural expressway
of the name. In short more than ten years, numerous research institution of Japan
carry on extensive and profound developmental research to various kinds of
guardrail structure, made the guardrail to set up the outline in 1965, to the scope
of application of the guardrail, structural design, the function has required,

constructed such respects as installation ,etc. and made the clear regulation. Have
so far formed two kinds of typical guardrail forms in the United States and Japan.
Other a lot of countries, have roughly launched the research of the design
standard of the guardrail structure of each country in succession too in 50 , the
sixties.
Hyundai Motor's production technology and technological level improve day
by day, the speed of design of the vehicle soars; At the same time there is a very
great demand too for the speed of operation as the main artery that is transported
fast in the expressway The vehicle that the speed is lower than 70kmh has
already forbidden entering the expressway now, and common speed of going on
the expressway is all in above 100kmh. People in addition driven by the
interests, overload and is it become thing that remain incessant after repeated
prohibition already to overspeed. Confirm with different fields high speed that
automobile go take , then a following one to is it collide improvement of speed to
result in. Because the impact kinetic energy and its quality of the automobile are
in direct radio, and its the travel speed is the square of in direct radio, once
exceeding outside the outlet or accident of bumping against the roadside barrier
of high-speed automobile that goes , impact its violent degree will increase
obviously , cause heavy danger to passenger, the rational establishment of the
semi-rigid guardrail is more meaningful at this moment.
In recent years, the recoverable amount of motor vehicle of our country is
increasing constantly, the following road traffic accident is soaring constantly too.
Show according to the recent statistical data , the traffic security situation is still
very severe , the traffic accident is threatenning the social economic development
and security of people's lives and properties seriously. Expressway guardrail
concern life security of people, at the same time for mould new image of traffic
safety of road of our country have great meanings, should launch the profound
research of relevant respects in a more cost- effective manner . With flourishing

development of road construction of our country and the advancing triumphantly
of development of western regions, the demand of the guardrail will increase
rapidly, and the security anticollision guardrail that really accord with the
situation of road traffic of our country is a basic meaning and long-term vitality.
This too puts the problem urgently to be solved in front of our country scientific
workers of traffic safety of the road.


公路防撞护栏体系
随着经济建设的发展，各种现代化的交通设施，如高速公路、城 市立交、
高架道路在交通运输中所起的作用日益增强，而交通运输的发展也导致了交
通事故的急 剧上升，交通安全己经成为一个世界性的大难题。
刚性护栏是受汽车冲撞基本不变形的护栏形式，一般 指混凝土护栏混凝
土墙板式护栏采用“安全外形”的概念，主要通过外形坡度不同的侧面，使
汽 车减速，爬高，转向，这种护栏设计能有效的使碰撞角小于100的中型轿
车改向，并使汽车不受或受较 轻的损伤，当碰撞角度、碰撞速度较大时，汽
车损伤严重.
安全护栏的形式按刚度的不同可分为柔性护栏、半刚性护栏和刚性护
栏。1) 柔性护栏一般指 缆索护栏,是一种以多根施加了预应力的缆索固定于
支柱上的结构,完全依靠缆索的拉应力来抵抗车辆碰 撞,形式美观,行驶时没
有压迫感,但视线诱导较差,造价较高,一般不用。2) 半刚性护栏一般指梁 式
护栏,是一种用支柱固定的梁式结构,依靠护栏的弯曲变形和张拉力来抵抗
车辆的碰撞。梁式 护栏有许多种,应用最广泛的为波形梁护栏。具有一定的
刚性和韧性,损坏后容易更换,能诱导视线,外 形美观。3) 刚性护栏一般指水
泥砼墙式护栏,是一种具有一定断面形状的水泥砼墙式结构,依靠汽车 爬高、
变形和摩擦来吸收碰撞能量。这种护栏安全性高,能有效防止二次事故,本身

不易损坏,维修费用低,但对车辆行驶有压迫感,对车辆损坏较严重。
高速公路上的安全护栏既要 阻止高速行驶的车辆越出路外,或穿越中央
分隔带闯入对向车道,还要能诱导驾驶员的视线,使车辆回到 正常行驶方向,
并将事故中恶性程度降低到最小。总之,高速公路安全护栏是减少交通事故
和降 低事故恶性程度的有效措施,但在不该设置护栏的地方设置护栏,反而
成为新的障碍物,增加了事故危险 。因此,对安全护栏的设计首先要掌握护栏
的特点,结合高速公路的交通条件,在满足护栏基本功能的前 提下,选用合适
的护栏形式,并采取合理的设置原则。
由于受到地形条件、投资和技术条件等 多种因素的制约,路侧难免存在
障碍物,对越出路外的车辆构成潜在的危险。路侧护栏仅设置在能降低事 故
严重度的地方,其设计原则根据人们对公路等级、交通量、车辆组成和路侧
特征等因素的主观 判断而确定。
最理想的护栏形式是既满足功能需要又成本最低,而且美观大方,并能
诱导行车 视线。缆索护栏适合有不均匀下沉、积雪、长直线、有特殊美观要
求的路段；混凝土护栏适合特别危险的 跨河大桥、悬崖等路段；波形护栏有
更大的适用性,基本上适合所有路段,特别是小半径弯道和需要诱导 视线的
路段。根据规范要求和湖南省多条高速公路安全护栏设计经验,一般路段路
侧采用波形梁 护栏,个别特别困难危险路段采用混凝土护栏。
在交通量大的情况下,车辆高速行驶,一旦发生横越中 央分隔带的情况,
就可能产生严重的后果,因此,中央分隔带的宽度作为设置护栏的重要依据。
防撞垫是通过吸收车辆碰撞能量使车辆安全停住,并使车辆改变行驶方向,
避免司乘人员受到严重伤害 的设施。防撞垫成本低,具有很高的安全性能。
它主要应用于从无中间带向有中间带过渡、平交导流岛分 流点、有固定障碍
物等交通事故多发路段。防撞垫有夹层系统防撞塑料垫、填砂塑料桶防撞垫、
砂袋等多种形式。实践证明,防撞垫是一种有效的设施,它主要是降低事故的
严重度,而不是减少事故的 发生。随着我国高速公路的迅速发展,人们对安全
护栏重要性的认识有了很大提高,建造护栏时,要从性 能、景观和经济等多方
面认真比较,全面考虑。

防撞护栏包括四个方面的具体 功能：1)阻止车辆跃出路〔桥)外，对中
央分隔带而言，则要阻止车辆穿越中央分隔带而闯入对向车道 ；同时，还要
防出车辆从护栏板底下钻出，或将护栏冲断；2)护栏应能使车辆回复到止常
行驶 方向;3)发生碰撞时，对乘客的损伤为最小程度:4)能诱导驶员的视线。
从上述功能可以看出，护栏 必须具有相当的力学强度和刚度以抵挡车辆的冲
撞，防止车辆越出路(桥)外:同时，护栏的刚度又不能 太大，从而可以更好
地保护乘客免受伤害或减轻伤害程度。
实车足尺撞击试验是用实际汽车冲 撞护栏来模拟交通事故的一种研究
方法.它可以得到汽车在撞击过程中的运动轨迹和运动姿态、汽车与护 栏的
变形和损伤特征以及碰撞冲击力的数值等真实可信的技术参数，从而为安全
可靠的护栏结构 的设计和验证其它研究方法所得结果的可靠性提供了科学
的依据。现在，各国都把系统的实车撞击试验作 为对护栏研究的基本前提。
由于路侧护栏本身也是障碍物, 在条件许可的情况下, 路侧护栏应设< br>置得尽可能远离行车道。这样,偏离行车道的车辆能够最大可能地无事故地
重新驶回行车道。路侧 物体距离行车道边缘超过一定值后, 就不被认作障碍
物, 驾驶者一般不会因之降低车速或改变车辆在 行车道上的位置。这个距离
称为横向偏位。这个距离随车速的不同而不同,必须注意要确保路侧护栏与< br>其他构造物相连时适当的过渡设计；还应注意要确保护栏与障碍物之间适当
的距离。护栏碰撞时的 变形不仅是形式选择的重要因素,也是设置的重要因
素。尤其是被防护的障碍物是刚性物体时, 护栏与 物体之间的距离应足够大
以避免车辆在刚性物体上绊阻。合理设置路侧护栏对保证路侧安全的作用重大,但是路侧护栏形式的多样化以及设置的影响因素众多使得路侧护栏的设
计十分复杂。
护栏作为高等级公路上最重要的安全设施之一,能够阻止车辆冲出公路
或闯入对向行驶车道, 具有减少事故损失、保证行车安全的功能, 对于提高
司乘人员的安全感与舒适性, 提高公路运输的经济性与社会效益是不可或
缺的。
护栏是高速公路最为重要的安全设施之一. 按照吸能方式的不同,护栏

划分为以下3种典型形式:刚性护栏、半刚性护栏和柔性护栏 .护栏的作用是:
当汽车与护栏碰撞时,在自身不被破坏的情况下,吸收部分碰撞能量,并将汽
车导入行车道,保证汽车不越过护栏冲进相对车道或翻滚下护坡.因此对护
栏的要求是:必须具有足够的 强度和适当的刚度,同时要有较强的吸能特性
和一定的导向能力。
显然,对“汽车碰撞安全性”的研究与对“汽车-半刚性护栏”碰撞系统
安全性的研究是有区别 的,在“汽车碰撞安全性”研究中取得的研究成果也
不能直接用于指导半刚性护栏的设计；或者将汽车当 作无几何形状与尺寸的
质点或简单的弹簧-质量-阻尼系统,同时将半刚性护栏简化为线弹性体来研究半刚性护栏的设计技术如防撞机理等,研究中既没有考虑半刚性护栏的弹
塑性大变形对汽车运动规 律的影响,也没有考虑汽车的几何形状、尺寸及汽
车车体结构弹塑性大变形对半刚性护栏大变形的影响, 没有考虑材料的应变
率效应及惯性效应对汽车车体结构及半刚性护栏大变形的影响,更没有考虑
汽车与半刚性护栏各自自身及相互之间的接触与摩擦的影响。总之,没有考
虑任何耦合动力学现象。显然 ,这样得到的半刚性护栏设计技术并不能反映
问题的本质,其结果将不利于特、重大恶性交通事故防治水 平的提高。
我们认为,在汽车撞击半刚性护栏这一事件中,汽车与半刚性护栏乃是
碰撞系统中 不可分割的两个组成部分,二者相互耦合、相互影响,共同构成了
一个有机的整体。在汽车撞击半刚性护 栏的过程中,汽车与半刚性护栏之间
会发生接触,且发生接触的部位与接触面积会随着汽车的运动而发生 变化,
变化的接触区域会产生变化的接触力与变化的摩擦力,在变化的接触力与变
化的摩擦力的 共同作用下,半刚性护栏及汽车车体结构都会发生大小与部位
均变化的大变形(这种大变形常常与材料的 应变率效应及惯性效应密切相
关),这种大变形又会引发新的接触(包括汽车车体结构与半刚性护栏各自 的
自接触及部位与面积处于变化中的相互之间的接触),继而影响接触力与摩
擦力的大小与方向 ,影响汽车的运动轨迹,这种互反馈作用将使“汽车- 半刚
性护栏”碰撞系统处于特定的耦合冲击形态之中。
现在,人们正在将结构碰撞动力学的基 本原理应用于其他相关领域,其

中包括对半刚性护栏的研究,但由于专业划分的制约,在 半刚性护栏的设计
技术研究方面,仍然未取得突破性的进展。通过对碰撞过程中车内人体的响
应 特性分析,找出碰撞过程中汽车可能出现的各种运动规律对车内人体冲击
响应的影响规律,据此确定碰撞 过程中最有利于车内人体安全的汽车理想运
动规律。
本项研究与以往的研究也是不同的。汽车 的碰撞安全性研究已有大量研
究成果,作者以前也进行过大量的汽车碰撞安全性研究,但研究的都是汽车
安全标准中规定的汽车撞击刚性墙这类特殊工况,研究的目的是判断汽车结
构的力学特性是否合 适及如何改进汽车结构设计,建立的汽车碰撞模型虽然
非常复杂,但那是为确定汽车结构的力学特性服务 的,没有也不必要考虑被
撞击对象对汽车结构力学特性的影响。而对半刚性护栏防撞机理的研究,虽然也要考虑汽车结构的力学特性(在以前的研究中建立的汽车碰撞模型经过
处理后可以为本研究服务 ),但更重要的是要考虑半刚性护栏的力学特性对
碰撞过程的影响、及汽车与半刚性护栏之间通过接触界 面而建立起来的各种
耦合现象,显然,这样的研究与以前的研究是不同的。
“汽车-半刚性护 栏”碰撞系统完整耦合动力学大系统模型的建立是最
关键性的问题。模型中既要考虑半刚性护栏与汽车各 自的弹塑性大变形现象,
又要考虑半刚性护栏与汽车各自的几何形状与尺寸,还要考虑汽车与护栏之间的接触与摩擦等复杂因素,采用有限元模型比较合适。为兼顾计算精度与
计算效率两方面的要求, 模型的求解拟采用显式积分格式,具全部单元均采
用一点积分与前置参数砂漏控制技术,以提高计算速度 。为使建立的大系统
模型能够比较方便地用于各种半刚性护栏结构形式与设计参数的研究并兼
顾 模型的规律,拟建立一个通用的汽车简化模型,并根据需要建立由若干半
刚性护栏模型及其特征组成的护 栏模型库。
针对汽车构造复杂且现有的用于汽车碰撞安全性研究的汽车计算模型
过分庞大的特 点,拟在现有汽车碰撞安全性研究成果的基础上,对汽车碰撞
安全性研究中常用的汽车碰撞模型进行合理 简化,建立简明、直观、快捷、
科学的汽车简化模型。简化模型可以采用四节点壳单元与八节点实体单元 构

成的混合模型,将汽车上可能与半刚性护栏发生接触的部分用壳单元模拟,
其 余部分则采用实体单元模拟。
应用“汽车-半刚性护栏”碰撞系统完整耦合动力学模型,进行结构设计
参数的灵敏度分析,且首先研究半刚性护栏结构形式对碰撞过程中汽车实际
运动规律的影响规律 ,以确定使汽车实际运动规律与其理想运动规律最一致
的最优结构形式。然后,针对最优结构形式,继续 应用“汽车-半刚性护栏”
碰撞系统完整耦合动力学模型,研究结构设计参数对汽车实际运动规律的影< br>响规律,以确定最优设计参数。
可减少碰撞试验次数,获得可观的直接经济效益。长期以来,对 半刚性护
栏的设计,都是采用经验设计方法、半解析技术及试验方法混合进行的,尽管
可以设计 出可行的护栏,但单凭试验与试奏既费钱又费时,很不合算,且难以
使半刚性护栏的安全性水平处于最优 状态。如果有半刚性护栏设计新技术作
指导,就可以在设计阶段消除安全隐患,减少碰撞试验次数,每减 少一次碰撞
试验,可节约10-20万元。此外,能够优化护栏结构形式及设计参数,解决了
传 统方法难以解决的问题。
半刚性护栏防撞新机理主要用于高速公路和汽车专用一级公路上半刚
性护栏的设计与改进,当然,也同样可应用于其它各级公路上的半刚性护栏
的设计与改进。
然 而,汽车具有的冲击动能与其行驶速度的平方成正比,高速行驶的汽
车一旦发生越出路外的交通事故(这 类事故占交通事故总数的比例在普通干
线公路上约为45%、在高速公路上约为30%),后果将更加严 重。此时,设计不
合理的护栏将成为危险的摆设,进而严重影响高速公路及高等级公路的有效
利 用,不能充分发挥高速安全运输的优势。实践表明,半刚性护栏是一种性能
很好的护栏形式,已经在世界 范围内得到了广泛应用,由于基于半刚性护栏
防撞新机理的半刚性护栏设计新技术能够使半刚性护栏的高 速碰撞安全性
能得到进一步提高,对车辆越出路外这类交通事故(此类事故是造成特、重大
恶性 交通事故的主要原因之一)的防治有重要意义,因而具有广阔的应用前
景。

对 半刚性护栏防撞新机理的研究是确保公路交通运输系统实现高速安
全运输目的的基础研究之一,是一个多 学科相交叉领域的研究课题,具有重
要的学术研究价值和应用前景。它突破了以往专业划分的制约,将“ 汽车-
半刚性护栏”碰撞系统作为一个耦合的大系统,从确保车内乘员碰撞安全水
平最优的角度 出发,研究碰撞过程中汽车应具备的理想运动规律,在此基础
上,通过建立“汽车-半刚性护栏”碰撞系 统耦合动力学仿真模型来研究护栏
防撞新机理,是对传统护栏设计技术的重大突破,是提高半刚性护栏设 计水
平的前提条件,对道路交通事故中特、重大恶性事故的防治具有重要的意义,
因此,应大力 开展对它的研究,为确保道路交通安全水平的提高、塑造交通运
输产业新形象奠定技术基础。
刚性护栏和半刚性护栏是高速公路上重要的安全设施.研究表明,刚性
护栏在事故碰撞中虽然基本不变形 ,但由于本身结构刚性大,不但吸收能量
的能力低,而且容易造成二次事故.半刚性护栏是一种连续的梁 柱式护栏结
构,由于有一定的刚度和柔性,具有一定的能量吸收能力,可大大地减轻对乘
客和车 辆的伤害,故已广泛地应用于公路工程中.波形梁护栏是半刚性护栏
的主要形式,对其进行安全防护性能 和能量吸收能力的研究,将对山区高速
公路的建设起指导作用,并为部分复合材料护栏的设计提供理论依 据.
改善地下空间的环境质量和通风效果，为乘客提供舒适的乘车环境，为
车站设备和工作人 员提供良好的工作条件，使地下环境得到有效控制。满足
在车站或附属用房发生火灾事故时，进行有效排 烟与通风，保证乘客安全疏
散及工作人员和设备安全。列车阻塞故障时，能够维持车厢内乘客对新鲜空< br>气的需要。
美国从1920年起就开始了护栏的研究与使用，在理论分析和模拟实验
的 基础上，通过实车足尺护拦碰撞验证实验和公路上的应用实践，积累了大
量的资料和丰富的经验。美国国 家研究会交通研究所在1981年制定了高速
公路安全设施的评价标准，在1970年和1986年前后 组织了高速公路护栏结
构及各种安全设施的一系列的研究工作以及编写各种设计规范。法国、英国、德国等国家也在很早就开始护栏结构的研究工作，建立健全了一整套的实验

设施和相 应的实验规程，从理论和实验上研究了多种类型的护栏结构。日本
于50年代开始这方面的的研究工作， 并在名神高速公路开始正规使用护栏。
在短短十几年中，日本的众多研究机构对各种护栏结构进行了广泛 深入的开
发研究，于1965年制定了护栏设置纲要，对护栏的适用范围，结构设计，
功能要求 、施工安装等方面作出了明确的规定。至此形成了美、日两种典型
的护栏形式。其它许多国家，大致在5 0、60年代，也相继开展了各自国家
的护栏结构的设计标准的研究。
现代汽车生产技术和工 艺水平日益提高，车辆的设计速度攀升；同时高
速公路作为快速运输的大动脉对运行车速也有很大要求； 现在车速低于
70kmh的车辆已经严禁进入高速公路，而高速公路上通常的行驶车速都在
10 0kmh以上。另外人们在利益的驱使下，超载和超速已成为屡禁不止的事。
所以以各方面都印证了汽车 行驶的高速化，于是随之而来的是导致了碰撞速
度的提高。由于汽车的冲击动能与其质量成正比，与其行 驶速度的平方成正
比，高速行驶的汽车一旦发生越出路外或撞到路边障碍物的事故，其冲击的
剧 烈程度会明显增加，从而对乘员造成更大的危险，此时半刚性护栏的合理
设置就更有意义了。
近年来，我国机动车保有量不断增长，随之而来的道路交通事故也在不
断攀升。据最近统计资料显示，交 通安全形势依然十分严峻，交通事故严重
威胁着社会经济发展和人们生命财产的安全。高速公路护栏关系 到人们的生
命安全，同时对于塑造我国道路交通安全新形象具有重大意义，理当大力开
展相关方 面的深层次的研究。随着我国公路建设的蓬勃发展和西部大开发的
高歌猛进，护栏的需求量将迅猛增长， 而真正符合我国道路交通情况的安全
防撞护栏才有根本意义和长远的生命力。这也是摆在我国道路交通安 全科学
工作者面前亟待解决的问题。
公路防撞护栏，六英尺长，3.5英尺高，底部2英尺宽 ，由于它取得专
利权的设计，是唯一的自锁护栏形式而不需要额外的辅助设施。
没有任何护栏 能够和公路防撞护栏一样在不需要额外设备的情况下自
锁，例如缆索、皮带、直杆或者联结体。

此外，当残余锁定临近的护栏时，由于公路防撞护栏的独特设计在每个
护栏联结处在任 何方向允许超过十五度的弯曲构造。没有其它护栏能够做到
这项要求。
同样，公路防撞护栏设 计用来增加遮蔽物标记和闪光设备，因为在狭槽
位置实施这种设计，并且更容易机动运输，因为它重量轻 ，并且在每个护栏
上有两个运送槽。
公路转角连接护栏设计用来作为护栏连接单元，使左右转 向都允许通
行，或者同时转向通行，当把所有的护栏都连接到一起时转向能够从七十五
度到一百 零五度。除此以外，转角连接护栏允许最初防撞护栏路线紧接连接
护栏的延伸部分向左或向右。
重量轻并且容易搬运，公路转角连接护栏长宽都是2英尺，高3.5英尺，
设计用来符合公路防撞护栏 。
与转角连接防撞护栏填充孔直接相邻的是一个销钉从底部延伸到顶端
以便加固立柱能够向下 嵌入填充孔。
公路防撞护栏装配对于高速公路来说是一个加固系统，分布并且转移可
能出现的 汽车冲击力，所以全面的高速公路护栏系统将更加完整有力。护栏
高速公路装配系统符合公路硬件参数平 台350标准，实车撞击试验3辆卡车
和小汽车碰撞，已经被美国联邦公路局证实用于高速公路工程建设 ，这个区
域主要的汽车行驶速度高达每小时60到100英里。
装配高速公路防撞护栏是构成 钢结构设计计划以便容易的设置公路防
撞护栏。这种装配具有两个独特的功能：具有坚固而又弹性的外表 面来抵抗
高速车辆的车轮和缓冲器的撞击，并且使各个护栏单元连接更牢固，创造一
个非常牢靠 的线性系统，这样高速车辆的冲击力被许多护栏均分，最大程度
减小撞击点的横向运动。
公路 防撞安全面板是用来确保周围安全，人群控制和主体场所保护。这
种6×4金属防护网连接护栏单元稳固 地安置在公路护栏上来提供稳定的8
英尺高持续的、完整的护栏体系，满足所有安全需要，可选择实心固 体材料、
遮蔽物或者交织链节。