Slide 1

Rock and steel samples The iron nail is badly rusted, while the zinc-coated nail looks brand new. The granite cobble stone is worn and rounded, but still has a lot of strength. In contrast, the old man-made concrete aggregate crumbles easily because soil conditions dissolved it. The moral of the story is that HOW we build things counts a lot. Soil conditions can greatly affect how durable and safe buildings are.

Slide 2

For mid-term question #6: Think of modern cars like a Hummer or Toyota Tundra. A Ford F-250 weighs about 8,000 pounds and full of technology. Faster and safer, but very expensive when damaged (easy to total it). We dont die as often (highway deaths are down even with increasing population, but we sure lose a lot of money because our stuff is so expensive

Slide 3

This weeks weather 104 degrees F what if today were humid also? n humid regions, 90 degrees F can be a deadly heat wave. Heat stress index adds a humidity factor to heat In winter, we add a wind chill factor to the cold.

Slide 4

See page 312 in the textbook

Slide 5

Page 70 Heat Waves Europe 2003 35,000 deaths due to heat, 14,500 in France

Slide 6

Temperature Inversions

Slide 7

Slide 8

Utah has some of the nations coldest winter temperatures we are far from the ocean, far from sea level and far from the equator. Peter Sinks presents ideal conditions for deep winter weather inversions cold air has no where to go, so it concentrates.

Slide 9

Heating & Cooling Degree Days - USA White and pink areas have no summer cooling load (> 65 degrees F) Red areas > 9,000 cooling degree days

Slide 10

Whats wrong with lots of water in the air on a hot day? -The water is hot also -Body perspiration by evaporative cooling cant occur if the air is already full of evaporated water -Why is there no wind chill factor with hot/humid air?

Slide 11

Wind Chill and Heat Stress Index pages 89 and 108

Slide 12

Wind chill - Skin has a boundary layer of warm, humid air that is removed by wind, resulting in wicking heat away from the body, making cold more penetrative.

Slide 13

Todays earthquake in China 6.9M -75 dead -Unreinforced buildings with mud roofs -Heavy rain preceded quake -Water adds weight and helps loosen and dissolve earthen material.

Slide 14

This is the blocked drain at the Constitution Park retention/detention basin. They used sandbags AND a.... levee.

Slide 15

I wonder why one drain is double-blocked, but with a gap what is the value of sandbags with a gap?

Slide 16

If a duck is settling in, is the basin for retention or detention?

Slide 17

At Allreds house flash flood conditions will be avoided by putting careful drains underneath hard surfacing so that rain water has some place to go sink into the ground. Good drains will also help prevent damaging and slippery ice on the surface.

Slide 18

Excavate, remove fines (fine material) and replace By removing clay and silt, the remaining cobblestones add strength underground and provide pore spaces for collecting rain water until it can finish draining into the soil. Even in dry Utah, flash rainstorms can cause severe surface flooding. Drains can easily get blocked by debris.

Slide 19

Is it true that its not so much where you build as HOW you build?

Slide 20

Miller campus steel-frame building, with lightweight walls and ceiling easily shaken by a passing train, but is probably wont fall down in a quake.

Slide 21

Reverse the concept that modern life is turning hazards into disasters and disasters into catastrophes: instead, by making hard choices to fund better infrastructure and building practices, we turn catastrophes back into merely cracks in the sidewalk.

Slide 22

Some Intervention Terminology: Drain tiles, surface & underground Grading: terraces, lower angles Reduce loading by buildings and vegetation Earth anchors and other retaining structures such as gabions, pilings, seed mats, engineering fill, bolts, spread footings. Do these play a role in Chapter 8 Soils and Subsidence?

Slide 23

Creep Slump Flow Fall But what about soil structure?

Slide 24

Lava beds in southern Idaho old sediments (sandstone) with fossil fuels oil, coal, gas, shale, tar sand Volcanoes and cinder cones Lava beds in southern Utah Geothermal heat on west side of Utah

Slide 25

But it is also true that we are running out of good building sites on the best ground: Not too wet and not too steep?

Slide 26

Has this slope changed its angle of repose? Depends on what is done with the steepened portions

Slide 27

Gabions, retaining walls, earth anchors, drain pipe, surface water removal, engineered fill material

Slide 28

Some students conclude to be cynical Were damned if we do and damned if we dont. Is that really true?

Slide 29

Many land formations have been vertically deforming for millions of years, but that does not mean we must: - add load to vulnerable soils (such as by heavy buildings); - pump out water; - pump in water; - remove minerals; - use weak foundations; - build in chutes or flow paths;

Slide 30

Chapter 8 Mr. Allreds Sets of Threes in Soils Core, mantle and crust. Crust as bedrock, regolith, soil Soil as mineral, air/water, organic Mineral as sand, silt, clay

Slide 31

Regolith: blanket rock, fractured, crumbling transition between bedrock and soil Regolith is being weathered physical and chemical breakdown

Slide 32

Soils Pyramid page 246 Source unknown: probably googleimages.com and USDA, undated. This set of three is mostly about how well soils drain, how permeable they are, how well water percolates through. In the case of clay, how stable the soil is when wet.

Slide 33

Highland campus ash can

Slide 34

Why?

Slide 35

Soil Profile or Horizons Point out bedrock, regolith, soil Source: EnchantedLearning.com and Googleimages.com Page 243

Slide 36

The presence of distinct soil horizons suggests stability of the ground it takes hundreds, even thousands of years to develop soil horizons (except in some extremely wet/hot climates)

Slide 37

What can you conclude if excavation shows unconsolidated, unsorted materials of different types? 1. Un-layered, un-sorted soils are likely produced by recent cataclysm, like quakes, landslides, etc. 2. Strongly layered soils indicate long-term stable conditions at that location, probably less prone to soil failure.

Slide 38

Allred excavation: 1. Humus layer 2. Root layer 3. Salt layer 4. Cobbles

Slide 39

Hardpan or compacted soils have been cemented by chemical action to be nearly impermeable. In contrast, permeable soils allow water to percolate through, helping prevent surface flooding or soil saturation that can cause building damage by subsidence or collapse.

Slide 40

Alluvial fans or river deltas page 248 Implications? What about a fan off-set?

Slide 41

What is wrong with building on: - alluvial fan? - river delta? Alluvial fan with an off-set?