-
7 Road
Engineering
Ⅰ
: Road Design
Horizontal and Vertical
Alignment
道路的平面和纵断面设计
1 Background
本文背景
One
definition of a visually attractive and
unobtrusive highway is the
degree to
which the horizontal and vertical alignments of
the route have
been integrated into its
surrounding natural and human environments.
This takes careful planning and design,
as noted in the AASHTO Green
Book:
Coordination of horizontal alignment and profile
should not be
left to chance but should
begin with preliminary design, during which
adjustments can readily be made ... The
designer should-study long,
continuous
stretches of highway in both plan and profile and
visualize
the whole in three
dimensions.
一条公路是否引人注目取决于这条公路的平面和纵断面设计与
周围环境的融合程度，这需要认真的规划和设计，就像
AASH
TO
Green
一书中提到的：
“水
平面的位置和分布的协调不应该由可能性
决定，而应该是由容易调整的初步设计决定……
”设计者应进行长时
间的研究，
并具有把整个不断延伸的公路的
平面和剖面形象化的展示
在三维空间中。
This application of a holistic approach
to highway design, where the
road is
integrated into its surroundings, separates the
outstanding
project from one that
merely satisfies basic engineering design
criteria.
An excellent description of
this holistic design process is contained in the
publication Aesthetics in
Transportation, from which the following is
excerpted: A general rule for designers
is to achieve a
“
flowing
”
line,
with a smooth and natural appearance in
the land, and a sensuous,
rhythmic
continuity for the driver. This effect results
from following the
natural contours of
the land, using graceful and gradual horizontal
and
vertical transitions, and relating
the alignment to permanent features
such as rivers or mountains.
这种对于公路设计的整体分析，
应用在道路融入周围环境，
将
杰
出的项目从仅仅满足基本的工程设计标准的项目中分离出来等方面。
< br>对于一个良好整体设计过程的描述被写在已出版的《
Aesthetics in
Transportation
》一书，摘录如下：一般意义上
的设计者是用在地上
光滑和自然的外表实现“流动”的线，具有感官上的节奏感和连续性
的
掌控者。
其结果是适应土地的自然轮廓，
运用优美渐变的水平和竖直
线过渡，并对河水和高山这类永久特征性进行调整。
2 Horizontal and
Vertical Alignment Considerations
平面和纵断面设计中的考虑因素
The greatest opportunities for
influencing the horizontal and vertical
alignments of a highway occur during
the planning and preliminary
engineering phases associated with a
new-location facility. The designs
of
such facilities have the most dramatic effects on
the natural and
human environments
through which they pass.
影响高速路平面和纵断面定位的
最大的机会出现在规划和初步
设计阶段并与新位置设备有关。
这
些设备的设计对于道路所通过的自
然和人文环境具有最大的效果。
The more typical design
problem faced by today
’
s
highway
engineers is the improvement of
an existing highway or street. In many
instances, the basic alignments may
have been established well over 100
years ago. Regardless, the same basic
design principles with respect to
horizontal and vertical alignments can,
however, be applied to both new
and
existing facilities.
当今高速公路设计者最典型的问题是对于
已有的高速公路和一
般道路的修缮。很多时候，原有的道路可能已存在超过
100
年。不
管怎样，
重视
水平和竖直定位的最初的基本设计原则能，
并能很好的
应用到新
的和现有的设施中。
Important points to consider regarding
horizontal and vertical
alignments are
that they should be consistent with the
topography,
preserve developed
properties along the road, and incorporate
community values. The superior
alignments are ones that follow the
natural contours of the land and do not
affect aesthetic, scenic, historic,
and
cultural resources along the way. Construction
costs may be reduced
in many instances
when less earthwork is needed, and resources and
development are preserved. It is not
always possible, however, to avoid
having an impact on both the natural
and human environments. That is
why the
superior alignments incorporate input received by
the
community through a participatory
design process.
重要的是需要考虑平面和纵断面
,
他们应该符合地形
,
沿路保护
开发属性
,
并整合社区的价值观。那些遵循自然轮廓的土地
,
不影响美
观
,
风景优美、历
史和文化资源是优美的对齐。在许多情况下建设成
本可能会减少
,
需要更少的土方工程、资源保存和发展。然而
,
为了避
免对自然和人类环境产生影响，
这并不总是可
能的。
这就是为什么通
过参与设计过程将收到的社区上级对齐。
When possible, the alignment should be
designed to enhance
attractive scenic
views, such as rivers, rock formations, parks,
historic
sites, and outstanding
buildings. The designation of certain highways as
scenic byways recognizes the importance
of preserving such features
along our
Nation
’
s roadways.
在可能的情况下
< br>,
对齐应旨在提高迷人风景的观点
,
如河流、
岩石
,
公园
,
历史遗迹
,
杰出的建筑。
某些高速公路以及我们国家的道路景观
通道的设计是认识到保持这些特性的重要性。
Equally important as the consideration
of the horizontal alignment
is that of
the facility
’
s vertical
alignment. A number of factors influence
the vertical alignment of a highway,
including the following: (1) Natural
terrain; (2) Minimum stopping sight
distance for the selected design
speed;
(3) The number of trucks and other heavy vehicles
in the traffic
stream; (4) The basic
roadway cross-section; i.e., two lanes versus
multiple lanes; (5) Natural
environmental factors, such as wetlands and
historic, cultural, and community
resources.
考虑设施的平面和纵断面是同样重要的。
许多因素影响高速公
路的纵断面线型
,
包括：
(1)
自然地形
; (2)
根据最
小停车视距选择设计
速度
;(3)
卡车
的数量和其他重型车辆的交通流
;(4)
巷道基本截面，
即两
条车道与多个车道
;(5)
自然环境因素
,
如湿地、
历
史、
文化和社会资源。
3
Combination of Horizontal and Vertical Alignment
平面和纵断面的组合设计
The interrelationship of
horizontal and vertical alignment is best
addressed in the route location and
preliminary design phases of a
project.
At this stage, appropriate tradeoffs and balances
between design
speed and the character
of the road-traffic volume, topography, and
existing development-can be made. A
mistake often made by
inexperienced
engineers is designing the horizontal alignment
first and
then trying to superimpose
the design onto a vertical profile. Because
they must be complementary, horizontal
and vertical geometries must
be
designed concurrently. Uncoordinated horizontal
and vertical
geometries can ruin the
best parts and accentuate the weak points of
each element. Excellence in the
combination of their designs increases
efficiency, and safety, encourages
uniform speed, and improves
appearance-
almost always without additional cost.