Have you ever wondered how earthquakes affect bridges. I must admit that I had not thought about that subject until quite recently. Now I do.

1. How Do Earthquakes Affect Bridges

2. Have you ever wondered how earthquakes
affect bridges.

3. I must admit that I had not thought about
that subject until quite recently. Now I do.

4. In the last few years in the North Texas area,
we have been experiencing a significant
increase in the frequency and magnitude of
earthquakes.

5. There are many who say that this is the
result of the exploration for underground
gas reserves, which has become widespread
in this area.

6. No matter the root cause, the subject of
how earthquakes affect bridges is now on
the minds of many.

7. How Earthquakes Affect Bridges Has Many
Factors

8. When evaluating the affects of earthquakes the
most important factors to take into account are
the magnitude of the earthquake, the distance
from the epicenter of the earthquake and the
geologic conditions at the site of the earthquake
itself.

9. When it comes to how earthquakes can
affect bridges, the main concern is the
damage that can be caused by the ground
motion that the earthquake creates.

10. Going deeper into this subject, one must
take a look at the local geology and type of
soil that the bridge has been built upon.

11. When soft soil lies on top of hard bedrock
the ground motion is amplified, this is known
as ground-motion amplification.

12. This type of amplification can result in much
greater damage, even from bridges that are
quit a distance from the epicenter of the
earthquake itself.

13. In fact, soft sandy soils can actually be
liquefied by strong ground motion in a
process call liquefaction.

14. When liquefaction occurs, the foundation of
structures, like bridges, can be completely
compromised.

15. Whether Earthquakes Affect Bridges
Depends Greatly On the Magnitude

16. The general rule of thumb is that
earthquakes below a magnitude of 4.0 do
not cause infrastructure damage.

17. Since 2013 there have been over fifty
reported earthquakes in a two mile area
alone just west of the Dallas city limit.

18. None of these earthquakes have been
recorded to be above 4.0.

19. But there have been earthquakes in the
North Texas area in the past that have been
above 4.0.

20. The largest recorded earthquake in the
State of Texas occurred in 1931, when a
magnitude 5.8 earthquake was recorded in
far West Texas near the town of Valentine.

21. Highway engineers have devised standards
in an attempt to earthquake-proof bridges
that have been built since the early 1990's.

22. Most bridges that we drive on daily were
built before these higher standards were
implemented however.

23. Today, the subject of how earthquakes
affect bridges is something that all of us
must pay attention to avoid a potential
catastrophe.