双语：

Introduction

简介

Building construction has evolved over time. Although the overall rationale for a structure—to provide shelter—has remained the same, the way we build buildings has changed as new technologies and techniques emerge.

随着时间的推移，建筑也在持续演化。虽然为人们提供遮风挡雨的初衷未变，但新科技和新技术不断改变着建筑的建造方式。

From a firefighting perspective, it is important to realize that the built environment that you respond to in your community is actually an aging collection of different types of buildings, incorporating a myriad of construction methods, materials, and design concepts, along with the hazards associated with each one.

管区内的各种建筑就像一个万年博物馆，不同的建筑类型，设计理念，施工工艺、材料以及它们可能潜伏的危险问题，每个消防员都不能忽视。

In essence, you must become the local “historian of building construction” to understand how the buildings you protect—and the people in them—will behave under fire conditions.

也许，当地的“建筑历史学家”就是对这项工作的最好诠释，当然这将有助于消防员预判建筑和里面的居民在火灾中可能的反应。

One thing that hasn’t changed, however, is the laws of physics.

但是，物理定律是亘古不变的。

As a fire fighter, you must have a working knowledge of how the forces of nature and humans cause buildings to collapse.

作为一名消防员必须具备基本的常识，比如大自然之力和人类是如何弄塌一栋楼的。

Anticipating the reaction of a particular building to these forces is essential to your safety.

预判这些力量对建筑物的影响关乎生死。

It is important, therefore, that you have an understanding of the basic concepts of construction.

因此，了解一些建筑行业的基础概念就显得极为重要了。

Despite the fact that learning from fire-ground experience is critical, you can’t rely solely on this to keep you safe.

虽然火场经验很重要，但书本知识同样不可少。

From experience, some fire officers have learned to make useful, but limited, judgments regarding the loss of structural stability in a fire.

有些指挥员可以依托经验对建筑物在火灾中失稳情况进行有效的，但存在局限性的预判。

Many of the commonly taught indicators, such as sagging floors, strange noises, and the like, may be cases of “too little, too late.”

一些常见的失稳信号，比如“塌陷的地板，奇怪的声响”等等，可能“太不显眼，太不及时”。

In addition, experience with one type of building element, such as solid sawn wood joists, is not valid for trusses or wooden I-beams.

此外，实心锯木托梁的经验是不能用在桁架或木制工字梁上的。

Relying on experience alone is not sufficient for today’s fire fighters; they must be aware of the theories and principles involved in building construction.

因此，对于当代消防员来说仅仅依赖经验是远远不够的，书本上的关于建筑的理论和原理也是必须的。

We will begin our study by looking at the greatest of all fire fighter enemies—gravity.

接下来，课程将从所有消防员的头号大敌—重力开始。

Gravity

重力

The force of gravity is the eternal enemy of every building.

重力是所有建筑永恒的敌人。

Twenty-four hours a day, seven days a week, gravity exerts a force on the building.

7X24小时，重力对建筑施加的作用年中无休。

Buildings may appear to be just quietly sitting on their foundations, but, in fact, they are under great stresses.

看上去，建筑好像只是静静地坐在基座上，但实际上它们承受着极大的压力。

Although this may not be apparent as you look at the structure, the stresses are there nonetheless.

虽然看不出来，但压力是实打实存在的。

By one means or another, in assembling a structure, the builder has defied gravity. Not all builders recognize this fact.

无论使用哪种方法，建筑物建造的过程就是对抗重力的过程。但不是所有建筑商能够意识到这一点。

The gravity resistance system in a building consists of all the structural elements and the connections that support and transfer the loads—that is, the forces attributable to gravity and other sources of stress on the structure.

建筑的抗重力系统由建筑中所有的构件和连接件组成，所有这些组件支撑和传递由重力和其他压力构成的负载。

Fire weakens and destroys the structural elements and/or the connections in a building, and places loads on some structural elements that cannot handle them, which can cause a collapse. Once the collapse starts, the results are unpredictable.

火灾会削弱和破坏构件和/或连接件，导致构件无法承受额外的负载，从而引发坍塌。一旦建筑开始坍塌，结果就无法预料了。

Some buildings are designed to be fire resistive. This means that to some degree they will resist fire-caused collapse.

有些建筑设计了抵抗火灾的功能，意思是在某种程度上可以抵抗火灾造成的坍塌。

The majority of buildings are non-fire-resistive, and thus may easily collapse as a result of assault by a significant fire on the gravity resistance system.

大多数建筑是不防火的，其抗重力系统受到大火的侵袭时非常容易坍塌。

往期内容：

第一章 序言

1001页：A008 消防建筑施工

1001页：A009 消防建筑施工

第二章 建筑基本常识

1001页：A011 消防建筑施工：建筑基本常识