Saturday, December 24, 2011

Some will understand

Buddha decided to teach what he had learned with the idea, "Some will understand".

Some of his "learning" was likely hunger induced hallucinations. Other were random good insights and summaries. Some are built on the tribal culture and religion of the time and location.

These are only my opinions on the various readings I have done.

Compassion and the elimination of suffering is the main concept. Buddha recognized that suffering is an inside job, a self induced feeling, and that that feeling can be nominalized by a series of concepts, beliefs, values, ways of thinking and actions. Various translations and repeated expressions create a range of ideas of what each component really says. The four Noble truths go something like this:
1.  Life contains suffering, pain, impermanence, toxicity, loss, stress, vaguity, distress, depression, pain causing things. The pain is an internal mental object, not a physical reality except if it is our body, but even then, the pain is a mental object. The unsatisfactory quality of life which is targeted mental object, the sorrow and trouble, the never completely fulfilling. We always want more happiness, less pain. But this ‘wanting more’,the longing, is itself the problem, the craving, the desire for more. Buddhism does help the physical, but first, it removes the internal mental object in ourselves.
2.  The second part is it is our cravings, our attachments, our selfish grasping after pleasure and avoiding pain that causes the problem. Our delusions of how life should be, our attachment to people, property, prestige, and money, our aversion to loss of people, property, prestige, and money, or simple attachment, delusions, aversions are the cause. Again, these are internal, mental objects. It is not necessarily the real loss, just the potential of loss. Many religions find it easier to have real poverty than deal with the mental potential of loss, or the issues that desire for these things can bring.
3.  the third is there is a solution to all this,
4. The solution is following the eight fold path to a peaceful serene state of mind.

Tuesday, December 6, 2011

Surrogate Measurement vs Real Measurement

Surrogate Measurement vs Real Measurement is an issue in many things beside soils. The medical industry uses surrogate measurement for a lot of things.

Surrogate measurement is the concept of measuring something that generally relates to a desired property, that is difficult to measure. The swelling potential of soil is time consuming test, but the moisture content, liquid and plastic limits can be determined in a day. There is a direct relationship between the liquidity index and the swelling potential, so we determine the liquidity index and imply a swelling potential.

As long as that relationship between the liquidity index and swelling potential holds, we are in good shape. But add any one of a long and growing list, and we are out to lunch by a long shot. Gasoline, any petroleum, soap, or even organic staining, and the correlation is out. Now we must do the full consolation with swelling, to find one point. We may need a number of points, depending on the situation. Each point is 12 days at least, if a (the) consolidation frame is available.
We would need to do the test to even find out that the relationship does not hold for this sample.

Those time do not include any sampling time involved, nor sample quality issues.

Now what about the medical field. wtf. They use more surrogates than we do in engineering. If you are producing enough iodine in you urine, you are not short. 20 years of misery, and Oh, you are not absorbing enough iodine. wtf.

Oh well shit happens. The medical industry knows what it knows, which is considerable less than they indicate that they know. If they do not deliver results, they do not have a solution. Trying something may be the only true test of whether it will work or not.

Monday, December 5, 2011

History


Quote from about:

History books tell us what historians have selected rather than everything that happened.

History, as recorded after the event is recorded by the survivors. What the concurred race was up to is speculation from artifacts and other evidence, not was going on. In my youth, I spent a bit of time with natives, and as a young man, I worked in the north among them. Few got the concept or idea of working for something, rather the concept of ownership of property was not in there philosophy.

The social, philosophical, living aspects just are not there. A people living hand to mouth, when presented with food, will not move from that spot until the food runs out. How does The Canadian Government deal with the native northern population, and population growth. Supply more food. How long does it expect us working stiffs to support such foolishness?



Sunday, December 4, 2011

Free Speech, Really

In Canada, do we have free speech, or free speech as long it agrees with the politically correct view? If I said that we have been providing for the northern Indians for them to reproduce in places that have not economic base, would I be in shit, if anyone read it?

The only reason to be in the north, in many areas, is to provide services to the natives, all on the taxpayers nickel. How long are we going to keep paying as the natives keep reproducing? Where is the occupy movement now?

Just bitching.

Tuesday, November 22, 2011

DM and the Knot Hole

Back when I was a wee gaffer, I grew up in a farming community that was fifty years behind the times and proud of that. Very few had electricity, or phone. Indoor plumbing was a path to the outhouse. Water came in buckets, was heated on a wood stove. Baths happened one per week. Schools were one and two rooms. I was the first year of busing, picked up on the public road, and dropped at school, when the roads were open, and the mud was not too deep. I did not get the privilege of walking to school up hill both ways.

Most Sundays the extended family attended church, if the road were clear, the truck running, and passable. When it got real cold, the truck did not run. Sometimes it could be started by pulling with the horses, or if a tractor had been started, the tractor. If that did not work, It was too cold anyway.

Winter stating of tractors required a pail of boiling water/antifreeze mix. With pure water, it would ice up inside the block, and that was not good. There was not enough anti freeze it it to leave it in the engine, just enough to stop the icing. After the tractor was put away, the anti freeze drained and hauled back to the house for reuse the next time the tractor was needed, usually for grain hauling, or grinding. The horses worked fine for manure hauling all winter.

Anyway, now that you know we were poor foke, who on Sundays went to a church in a small place, in the Hamlet, in a church that had been built by farmer volunteers, one of which had been a carpenter/steam engineer/farm building assembler as a young man, and another a bricklayer/mason, and another a oxen driver/oxen freighter/black smith- when the west was young, and many youths who need to learn what ever there was going.  It had a few issues here and there. The pews were made from dressed 1 inch pine. There were a few random loose knots, some of which the center core had fallen out or been pushed.

That church was heated by a airtight stove in the rear, and there was a pew next to the air tight, where my farther always sat so that he could "tend the fire" during the service without disturbing anyone.  It was likely the warmest seat in the house also, but that will be let slide by. Most of my male cousins sat in the rear opposite side, close to the door. I, been less than well behaved (talked a bit), was usually assigned a set at the far end of fathers pew, next to the window, and behind some elderly aunts and neighbors. The church  typically was getting warmish by the end of the service. Occasionally someone would come over and light the fire an hour before the service, so it would be somewhat warmer when we got there.

Anyway, DM, being a few years younger than myself, always was restless during the long boring services. His older brother, the one with a watch with a sweep second hand, often amused himself by counting the priests speaking rate. On cold days, the sermon could hit 150 words per minute, other time more like 100. On days when the priest had several services and lunch before, it could be down to 80 or 90. Something about the wine with lunch. It was something to do. Anyway, back to DM and this one knot hole. He found great joy sticking his finger in it and poking his sister who sat in front. We all found various things to do to pass the time quietly waiting for the time we could move about and do things.

Well as we age, even as youngsters time passes and fingers grow bigger and longer. Knot holes do not grow. You can see it now, the time his finger got stuck. Well his big sister leaned back, and pined his finger down to start with. Perhaps a bit of swelling happened. The poor little guy was trapped, with his finger in the knot hole for half the service, while the remainder of us had entertainment for the remainder of the service.

After the service, DM's father sent his brother over to the neighbors to borrow a saw. When DM heard that, he let out such a scream. "Not my finger, not my finger". Somebody got some snow and iced his figure, likely wetting it as well, and it came out. The saw was put to its intended us of making a knock to the knothole, so no kid could do that again. That was always know as DM knot hole after that. 

Monday, November 21, 2011

How Does One Organize Spaghetti

Spaghetti is a poison to one third of the population that is made from Durham wheat, a fall seeded variety of wheat, commonly called winter wheat. It is digested and absorbed slower that modern ground wheat, which makes it less damaging that red spring wheat but too hot for many of the descendants of norther European ancestry, or of Celtic or aboriginal ancestry. Modern wheat is even worse. Search Wheat Belly for more information. Add chemical fertilizer, and we have poison, but that is another story. See my other blogs for that stuff.

This is about sorting such things. When I was young, and writing computer programs with punch cards, with a stack a couple of yards high, and another yard of data cards, spaghetti program was the rage, with multi-branching logic streams, that lead to subroutines, functions, subprograms, error trapping routines, loop detection, file closing, m by n by o by g matrices, and other such things, all developed from pages and pages of flow charts and the like. What wonderful training for sorting spaghetti. Family histories resemble family trees with to much data, and no logical order to handle manipulable streams of unrelated data, something like sorting spaghetti to get it back into the package. Oh well.

I have several boxes of family records that I "inherited" from mother, that she, and some of my ancestors deemed important enough to save. It does not seem right that I throw them out. There also stories, bits of memory, that should be written so someone unnamed or even unborn could assemble these in something in the future. Who knows: a family trivia game? a computer game? a book? a blog? whatever.

We have no children to pass these on to, so I thought I would throw it out to the world and see what happens.    

Desiccation, Vibration, Rewetting

What happens when we take a soil, dry it out with big trees, so that it shrinks and cracks, vibrate and disturb that dry block of soil, so that some of those dry peds infill the cracks, add water via a wet summer, and what happens to the lateral pressure on adjacent house basement?

Who is at fault? the owner of the trees (2 owners, one has two, the other has about 10, but farther away), the person who did caused the vibration, or the homeowner for owning a house on high plastic soils?  Without any one, the problem would be lesser? The lawyers should have fun with that one.

Wednesday, October 26, 2011

Fill of unknown quality

The geotechnical investigation found fill. Now what?
Normal slab fill evaluation flow chart would look like this approximately:

Is the fill organic - if yes remove and replace.


If fill clean, do stepped test pits under the grade beam locations, through the fill, with densities and proctors. Steps provide access and benches to do densities without tieing up the backhoe. Mind OH&S. Under grade beam locations will less sensitive to the new backfill of the test pits.  


If fill is more than a year old, and density above 98%, good.


If density 98% to 95% expect some settlement, and allow for mud jacking in a few years, if settlements occur and is a problem.


If density <95%, rework or expect a lot of settlements, or structural pile supported slab. This can be done just in the office, where settlement is likely an issue.

It is the clients decision. The numbers may change with depth of fill and expected loads.

Tuesday, August 16, 2011

Tickets

Safety or Revenue?

Consider the "parking to close to a fire hydrant" or corner ticket for an answer. It it was for safety, the curb would be marked, so we were not guessing where the limit is at. There you simple answer. Revenue.

Photo Radar... Speed tax.

Interesting time we live in. The governments have become the highway men, robbing from the public traffic.

Other departments are just taxing to raise revenues for there wages. They produce little benefit. We live at a time of the acceleration of the decline of the western works try at democracy. Yes, I believe we have been in decline since about 1970. There is not a single date, as different parts or functions have different peaks. Communications, with the internet is changing the world fast.   

Monday, August 15, 2011

Bloody Big Trees

Once again, I have reviewed a residence that has undergone considerable damage from bloody big trees. This time, there was a new garage / storage library, attached to the house. Once again, I assume high plastic clay. There was an small existing garage that created uneven soil moisture (assumed). Floor slab movements since the first inspection indicate shallow highly non-uniform settlement. The entire garage on shallow piles, 12 feet, is also settling, more closed to the trees. This implies that the desiccated crust is thickening. The desiccated crust is the result of the first cycle since the deposit was deposited drying out. We are starting to see a lot of similar issues in that area. There is no easy solution, other than to construct on deep foundation, or no big trees.

The entire house is surrounded with massive spruce trees and little drainage. The major offending massive deciduous trees belong to the neighbor, and the City has several close by. Now what?

Friday, July 15, 2011

Beyond the scope

A client used one of our reports for application of work beyond the scope of the report, and the County used one line in the report as defense of a project, which it could not support. The client wants us to withdraw the restriction. Now what do we do?

First the report covered a building foundation and a slope stability of a critical portion of creek slope, but the no water features applied to the entire creek length through the property. The client build a storm water management facility, a holding pond, too close to the creek. It does not comply with Alberta Environment Guidelines in a number of areas.

We have not conducted analysis of the bank at that location. The client did not conduct any testing on the roadways; hence, they are not a good client.

So here is the essentials of the letter I provided.


As requested, we has reviewed geotechnical investigation at the above noted site.  The purpose was to examine our recommendations to disallow water features within 30 metres from the top of bank along the creek, for the purpose of allowing a storm water management facility (SWMF)  (storm water pond) at the top of bank at the south end.

First, any storm water pond must comply with Alberta Environment Guidelines for SWMFs. The proposed development is short in a number of ways, assuming the plan provided is the complete plan.

The report was conducted before any SWMF was proposed on any of the plans provided, and as a result, the SWMF was not considered. It is beyond the scope of the report, and the SWMF was designed and partly constructed without any geotechnical or enginnering input from us.

The water feature setbacks, for small slopes, are normally based on a soil dependent factor multiplied by the depth of the slope, and expressed as a distance from the top of the slope. For typical clay till, 6 to 8 times the depth of slope would be typical, in this case about 3 metres, producing a typical setback of 18 to 24 metres from the bottom of the toe. However, no testholes were conducted, and we are unsure if clay, clay till, of sand lenses are present at this location. No analysis has been conducted, and the required information has not been obtained. There is also a question of the point to measure from on the SWMF.

We expect that at this location, the 30 metre water feature restriction can be reduced, but without testholes, testing, and analysis, we are unable to logically provide an exact number at this location. In addition, there are inside pond slope issues and erosion issues that are not addressed in the plans provided to us.  A specific geotechnical investigation would be required to address the SWMF and the setback, along with redesign to comply with the current Alberta Environment guidelines. 

Monday, June 27, 2011

What / Who influenced my life

Who were the big influences in my life?

As I reach retirement, in this stage of semi-retirement, I have a bit of time to reflect, and answer for myself questions like who and what have been the influences, the turning points in my life?

My philosophy of life has in the early years was running from the farm, what now would be considered as an abusive environment, not toward anything. After escaping, I worked a few years, and one cold winter, decided to get a bit of education so that I would not need to work outside at a temperature of -54 F. I selected Civil Technology because I could qualify to enter the program, and afford it. The field I selected was soils, largely due to numerous jobs in it that year, and I did not like surveying or drafting, the other choices. The job I choose upon graduation was the first one offered (desperation). I did not even get an interview with the government, and they had lots of jobs that year (My English was not good enough).

I stayed at that job due to the lack of direction in my life, and parts of the job was interesting; I got to see much of Northern Alberta, a few days here and there, a few months here, a few months there. No fixity, drifting as directed, no real long range plan, in reaction to the construction industry, the whims of developers, the requirements of government, specifications, building codes, and occasionally because someone wanted or need information. Some of them actually listened to what we found and used the data we collected. Others did not. I thought I could do as well as they did. And I was still in the cold in the winters. It had become time to settle down. I needed roots. Entered engineering, not as the first choice, but as a potential career with decent prospects. I looked at psychology, or other soft sciences, but as Dick put it, after 6 years of study, you will likely be making less than you are now.

So off to Civil Engineering I went, graduated, and returned to my former employer. After a few years, I needed a change, and tried some peripheral areas of what I had been doing, and then went back. The crash caused by Trudeau's National energy program came and jobs engineering tried up. I tried, did bits and bites of this and that, but did not work steady for ten years. I took master level courses, and then I would get a job for a while. I ended up with the course work for more than a masters, but never got the requirements in time or did the thesis.  I considered moving to where the economy was better, but my parents were old and I felt tied to Alberta, to be close enough to help them occasionally. Trapped by guilt, duty, or the like; a source of resentment, and obligation, without any acknowledgement. Not a good situation. Then in the early 90's, the surplus of engineers was gone, and the economy had returned, but I no longer had the energy, the drive necessary to work the long hours that is required for the technical introvert with poorer English and a dislike of writing.

The psychological / philosophical influences can be simply listed, Dale Carnige, Norman Vincent Peal, Gabrante, Kay McKenzie Gold,  AA/OA, Engineering Management, Buddhist readings, and the Internet blogs. These all combined to form what I am today, a twisted work in progress.  The people that influence positively and negatively are numerous and as some remain active, I will not list then. For those that know, Harold, John and 'Wilson and Smith', change my life many ways. There was the girl that knew she was going to raise kids and sheep, that cause me to redirect my life toward something, rather than away from something.

Once I started down the canyon that my career was, there was no escape, just carrying on. When I got tired, I just drifted, and dealt with what came up. I took some detours, some dead ends, and many misdirects. Some were my own decisions, and some were bad information, fraud, deceit, and lies.

Along the way I realized that most people are motivated by there own values, usually greed or the pursuit of money, fame, not the good of humanity. They would do anything for money, or avoid failure. Fraud, theft, deceit, anything.

One of my former employers sold leased vehicles to a different leasing company and leased them back. He got some cash, but was paying two leases. He also stopped remitting the premiums to an insurance plan, and for a while paid the expenses, until it was discovered. He was COD most everywhere. Interesting times. Paychecks bounding, final expense claims not paid. Such fun. See you in hell, Billy.

Sunday, June 19, 2011

Frye and Swelling - Shrinking under buildings

Frye is a legal standard of evidence, the lowest of which is the opinion of an expert. That would be superseded by test data, and ultimately by proof.

With foundation movements, it is impossible to go back in time to monitor moisture change in the soil below a basement so absolute proof does not exist for a specific basement. It has been shown to occur in research.

A expert can look at a structure, in a area known to have high swelling soils, note the trees, perhaps some wetter areas near downspouts, and if there is a correlation with distance from a major tree and the amount of shrinkage, that is the floor points to a tree, it is likely that shrinkage is to blame. It it point up at a drain spout, or a source of water, swelling is likely.

Now to remove doubt, one step at a time. First to demonstrate the soil has swelling/shrinkage potential. There is a good correlation between Atterberg limits, a index test for classification, and swelling. That only tells us that the soil is capable of swelling or shrinking. Add some moisture tests, and we can know that it is within the normal range that shrinking and swelling occurs. When we have condition that is dryer at the tree, wetter away from the tree, for similar soil and strata, the data would suggest that the tree is drawing water from the soil. But all trees draw water from the soil, and most draw more adjacent to the tree than away. This can get altered where there is a drain spout at the tree. Ideally the best demonstration we ever get after the fact, is a high plastic soil, and higher moisture contents at the high points of the structure. A range of moisture can usually be established.

There are odometer tests, where a "undisturbed" sample of soil is placed in a testing apparatus, the height measured, it is saturated, loaded, in steps over time, and allowed to swell, consolidate, rebound, and the results are analysed. But usually the soils in the field are not saturated to start with, so it tells more about the soil and its potential than what actually happened.

Now for the complication. Lacustrine deposits are varved, that is there is a variation in the clay/silt ratio with depth, often varying 40/60 to 60/40 in a few inches, or a foot vertically and be visually indistinguishable. The Atterberg limits, moisture content, hence the swelling potential, and the moisture holding capacity also vary. Comparing the moisture's without Atterberg limits on each sample is little better that an option mixed with some test data.

Now if we do four testhole, to 12 feet, with 12 samples per testhole, do moisture on all samples, limits on all samples, at about $100 each plus sampling, logging, field time, you have a nice bill, for a better suggestion of the possibility. Some of that data will be meaningless, or misleading, so what to do, we ignore some of the tests.  Suppose we do four testholes to 12 feet, a sample/foot , moisture on all, and say 4 limits on selected samples. Now we are introducing bias of the geotechnical engineer who is selecting the samples to conduct limits on, unless we say something like even testholes at foundation level, odd testholes at 1 foot below foundation level. Then it is biased by the person selecting the testhole order or locations.

The location must be selected to show the range, 2 in the dry areas, 2 in the wet areas. Ideally for a house, we would like two in the high area, two in the low area. This may mean 2 inside, and two out. To make matters worse we may may looking for 2 percent difference dryer hole to wetter hole, when over a few inches, the soil may vary 4 percent vertically in one testhole, so "proof" is not always obtained. The suggestion may be there in the data, or perhaps not. So now we can have a question as to what the data really shows.

One testhole in a area expected to be wet, at a downspout not near a tree, and one near a tree, not near a downspout, can be the best demonstration variability, with moistures every 1 foot, to 3 or 4 feet below the foundation may be advisable and a few limits just below the foundation level.

Now testholes on private property requires two liability wavers, one from the home owner and the insurance company we are working for must be willing to pick up the risk of a unknown utility strike. All known utilities can be located, both public and private, and avoided.  This assumes that locations are available and accessible.

Next is the other issue, the method. Inside is hand work. Coring through concrete floors is messy. Hand auguring below is tough work, and requires a skill that must be trained into people doing manual work, as well as myself to observe, and a junior engineer to sample and log the testholes. This all assumes that there are suitable locations to conduct testholes. Where the house is surrounded with trees, the outside testholes can be a issue also. Finding a "wet locations" that is clear of utilities is not always obvious, and close to the house. The front or rear lawn, well away from the house is often the only choice. Close to a tree, or within the same from the tree as the house is is often the best available choice for the "dry location".

Wednesday, June 15, 2011

Residential basement

Residential basements, as part 9 of the ABC allows them to be built are fragile.  They just break to easily, when anything heavy get near them. This is a problem for anyone working around these thing. They are just dangerous.
Vibration can produce lateral loads on them and fail them. They rapidly break with swelling clay or shrinking clay.

Tuesday, June 7, 2011

Vibration

Vibration Damage is a insurance issue, in that every time a home owners feels vibration from a construction project, the owner claims damage occurred. Frequently, the damage is obviously preexisting. But occasionally damage from vibration does occur. Any time a compaction roller gets closer than 25 feet to a residential concrete basement, built to just the minimum Alberta Building Code standards, the lateral forces are high enough to potentially cause damages. Drop weight concrete breakers and big back hoes which lift and drop concrete, pile driving operations, deep soil compaction, and well fracing all can cause damage.

Wet soils and vibration sensitive silts are particularly bad. Wet soils lateral pressures attenuation is low. Vibration sensitive silt can cause settlement at considerable distance.  

Saturday, June 4, 2011

residential piles

I recently reviewed another residence in distress in which the garage piles had failed, the grade beam had failed and broken apart, the garage floor slab had heaved. Previously, the sidewalk had sunk and been replaced with unistone. The driveway was showing distress. Once more the sewer line was adjacent to the piles. What it all comes down to is eight feet of loose fill will settle 3 to 5 inches, dragging piles down when they are loaded. Unreinforced slab do not work. Unreinforced grade beams do not work. The final load was likely this winters snow load, and the piles failed rapidly, dropping one garage wall 3.5 inches at the front, and that corner of the garage grade beam bowed out 2.25 inches at the floor slabs. In addition the buck downs were 14 inches, leaving about 12 inches of concrete block under the man door.

When will home buyers be protected? Not under the current system of codes, permitting, and no quality enforcement. The government is only interested in the appearance of enforcement, the political necessary part. Mind you, this was a 27 year old house. Yard drainage was less than ideal.

Ultimately, the builder must held responsible for the structure for a long time. How can we do this? Ultimately, an independent third part should provide a code adherence certification, to be registered on the title. The code would need revision that no one would be happy with. This would produce a requirement that each excavation, and back fill, every bit of work on the property be tracked on the title; hence, the owner would know what he was getting, not if it was going to hold up. All the common shortcuts would not be permitted.

Many of the contractors are not even aware of the problems of common construction methods. Steel on the bottom of the concrete slab, unreinforced concrete construction, permitted in the building code is just wrong, for long life. The building code, federally created, modified and adopted by provinces, municipally sort of enforced model we have now does not work. Inspection is by "permitting companies", that can only make money by paying their "build code inspectors" less that the government would be required to pay, to do the same work for less money, or do less work. It is not logical to be able to do the work "profit" less than the government.

Thursday, June 2, 2011

Difficult Clients

Difficult clients occur. They just want what they want, even though what they want is impossible, or not what they need, or just not what we provide. That may be the easiest way to look at it, as simply not what we provide. If we provide something that will not work for them, it is difficult to get paid. That is what makes working with armatures so difficult. By armatures, I mean first timers, virgins, at what ever they are doing, property development, privates building house, home builders doing custom homes, or commercial work, commercial contractors moving to industrial or institutional work, or from the oil industry to our construction field.

We do what we do, but are willing to change as long as it does not compromise our own standards, ethic, or logic. We work on paper and in the real world. The two must match.

Some client are just not worth having. The liability is just to much for the money it will provide.

Wednesday, May 11, 2011

Extrapolation Beyond the Testhole Area

Extrapolation beyond the testhole area is dangerous and must be totally at the clients risk. A situation has arisen where the client want advise on a site adjacent to a building for a parking area. It was not included in the original investigation.  Any additional advice should be an extra.

The first recommendation should be testholes are required to provide the requested recommendations. We only know the soils at the testhole locations, and there may be only soils classifications that are relevant. Soil varies rapidly across a site.  Fluvial deposits vary rapidly across the direction of water flow, less along the flow, and the flow is constantly changing, so the direction is changing. As sediment is placed, the channel is filled in. When old braiding and oxbows occur, peat will grow. So when we find peat, is it a channel or bog? How uniform do you expect the geology to be?

We expect that there is peat on this site. With peat, they need to be aware that movement, settlement, will occur, and that the settlement can be substantial. Grades are important when settlement is expected, and a 1.5 metre pad over the peat is require, remember that peat is associated with water, so what do we really have?

Next, as fill will be required, we will need to confirm the clay is suitable, and is consistent with the clay assumed in the fill design. Settlement of any remaining peat will occur. How much settlement? Rule of thumb 50% +_ 25% of fill depth. OK. Another one for deep muskegs-- 1/2 the depth of the fill placed. Peat is fibrosis, shearing is often not the issue, just compression of the peat. Fabric or grid can also spread the load better, but does nothing for settlement. Low weight fill has been utilized a few times. Artificial foam has been proposed to be floated, but I have never seen. 

One more thing to think about.
   

Monday, May 2, 2011

Routine Buildings, required number of testholes for preliminary investigation.


Ultimately, the purpose of any geotechnical investigation is to obtain information about the unknown conditions that lie below the surface. Often the geotechnical investigation is the first information on the site, often before even the sight survey. We are exploring the unknown. After exploration, we only know the conditions at the testhole locations, but that can imply a variation between the testholes. We can have tremendous variation in short distances both vertically and horizontally.

The information required is to provide input into the type of foundation, design parameters, and other issues that can be expected. Two large “unexpected” costs often encountered are unsuitable fills and poor foundation conditions, requiring expensive foundations. The more information we provide, the better the owner can estimate the cost and performance before construction is started.

With fills, additional testhole may be required to examine the extent and depth of the fills. Environmental cleanup can be dangerous due to fill settlement downdrag on piles. Redevelopment sites often have old fill over old utilities. Old fill compaction was often poor, and old fills often contain garbage.

Heavy buildings, high retaining structures, elevators, and similar are not included in this section: heavy buildings may have special requirements. This is intended for one story industrial buildings, three storey or so apartments, motels, and other buildings, but may apply to others in a general way. Areas with complex geology may require additional testholes. Thalwegs, stream erosion channels, occur in bedrock and clay till formations. Native buried peat moss formations occur in geologically recent river and delta deposits.

The testholes are intended to provide an indication of the vertical and horizontal variability of the strength and settlement characteristic of the various geological strata to sufficient depth to support the expected loads. One testhole tell the conditions only where the testhole was at: we have no clue as to the variation across site. One testhole is suitable for lift stations, or similar very small structure.

Two testholes are suitable for linear structures, 100 to 200 metre long sewer, roadways;  50 metre short height retaining walls, add one per each additional 200 metres of roadway or sewer, 1 per each 50 metres retaining wall.

Three testholes is the minimum required to describe a plain in geometry; however, the contact between strata is seldom plainer, and especially water lain strata. Three testholes is suitable for buildings to 500 square metres, add 1 per 250 m2 to 1000, 1 per 500 thereafter. Personally, I would not build a house without 4 testholes.

Should something odd or expensive to deal with be found, additional testholes for clarification may be required. Old coal mines, undocumented environmental cleanups, any industrial use, or redevelopment site can be hazardous.  




Monday, April 18, 2011

Cognative Dissonance

Cognative Dissonance – psychological conflict resulting from incongruous beliefs and attitudes held simultaneously.

In engineering, it may be expressed in other terms.
Example, Beliefs
  1. Engineering is important; to do construction correctly is valued; I make my meager living as a “Professional Engineer”.
  2. Construction should be conducted as per the Alberta Building Code. 
  3. Some cases the Alberta Building Code is grossly wrong.
  4. Now what? We are forced to create an “artificial value” for an Ultimate Limit State soil strength, that has no physical significant, and calibrate it to the desired outcome of the building code.
Most foundation should be designed for the Service Limit State. In 40 years, I have not run across a condition that I would employ a Ultimate Limit States soil strength for design. Many of the methods of evaluation of the soil strata strength do not generate a ultimate value, largely due to the time required in clays, and the gross amount of movement that occur in such tests.
Pile load tests are as close to ultimate as we would ever come, and usually those are limited to something like 50 millimetres of movement before it is declared failed. The true pile capacity may be 1.01 to 2.0 times that amount, for discussion.
For a typical project there is a wide range of soil strengths, and all this soil data must be reduced to something that is manageable for design. That is more of an art than a science, since the reliability and variation of the data, the amount of data, the geology of the formations, and the type of foundation all play major roles in the final value. After we go through all that, then we have to fudge a number so that the final result will be correct, due to government insistence on a system of design that matches the structural concepts of how materials should behave, not reality.




Wednesday, April 13, 2011

Is there a Full Moon?



I received a call from a structural engineer, and he was looking for a way to find geotechnical information, the strength of the soil, on a specific site, on a particular pile type, without conducting a geotechnical investigation.

I suggested a load test, a procedure that will cost about twice what a geotechnical investigation would, but he could do it himself. He went away, happy.

Damn Lawyers



I was asked to do an inspection by a lawyer but they were only willing to pay if I could provide a specific outcome from that inspection. What do lawyers think engineers are? Prostitutes? Magicians? 

I declined the opportunity. 

Shrinking Clay


A problem that I see frequently in Edmonton is clay shrinkage below foundation causing substantial damage to houses, sometimes destroying the value of the house.

The typical situation is as follows:
1.      The house was built on wet high plastic clay. Much of Edmonton has high plastic clay at and below foundation level. 10 to 20% of the land was wet before development into housing.
2.      The home owners (Or the city, developers) plant trees that become large, and suck water from the soil. In dry years, there roots go to the wetter soil, often below houses. The roots extend under the exterior foundations and desiccate an amount of soil. Typically values may be 3 meters of soil shrink 3% causing a 90 millimetres of settlement. If the interior foundations are unaffected, there is a noticeable slope toward the tree, usually with cracking.
3.      Now you have a problem, without a good solution. The first part of the solution is to remove the trees. Next is to underpin, and thirdly, to level the house and repair the other damage.  As the desiccated material thickens, the depth required for underpinning increases. A geotechnical investigation is required to answer the question of how deep, and what about downdrag.
4.      We geotechnical engineers think trees are nice, but in high plastic soils, they should be at least twice the height of the tree away from the houses. That makes a city treeless.
5.      The city likes to plant elm trees along the roadways because they dry out the subgrade and improve the subgrade strength, reducing the pavement failure due to loadings. The down side is the houses on the other side of the trees suffer. Is the City of Edmonton responsible for the damage there trees cause to the private properties? How about your trees and the neighbor’s house? What about the neighbor’s trees and your house?
6.      Shrinkage is only reversible after the virgin cycle; the first time there is some nonreversible shrinkage. Most of Edmonton upper clays have been desiccated to some depth, the desiccated crust, typically 2 to 3 metres; most house foundations are in or below this. Often the desiccation results in thickening of the desiccated crust.  
7.      Watering of the trees and downspouts helps but not much. Many of the large trees will use over a cubic metre of water per day. Some 2 or 3 cubic metres.
8.      Downspouts create the other side, swelling of that clay which have been desiccated. Downspouts at trees may cause a yo-yo foundation.
9.    Now one more complication, add water after shrinkage has occurred, and we get swelling. Now swelling is pressure sensitive. The exterior foundations, interior foundation and floor slab all produce different contact pressure on the soil, so different amounts of swelling causes differential elevations across the floor. What fun the kids have chasing their marbles to the walls usually. Time   to adjust your tela-posts to keep your main floor level. If you have bearing walls in the basement, perhaps you will need to install adjustable posts. Allow for future movements by providing access to the post and slip joints in the walls or above the ceiling. 

Sunday, April 10, 2011

Alberta ABC Building Code Schedules



Ultimately, the Alberta ABC Building Code Schedules require a geotechnical engineer to make the statement that the project has been designed and constructed in accordance with the Alberta Building Code, the Geotechnical Investigation, and good engineering practices. In addition, there may be a requirement to agree with the recommendations of the geotechnical report, at least to not disagree with the report.

We will not tolerate the owner, structural engineer, or contractor withholding information required to verify that design complies with the Alberta Building Code, and provide ABC schedules. The Alberta Building code requires that all designs be conducted by ULS and checked with SLS, and the more conservative solution be adopted.

To this end we require the actual pile loads, live and dead, a site plan to verify the building is at the same location and elevation as the geotechnical investigation, and also the geotechnical investigation must generally comply with the Canadian Foundation Engineering Manual as good engineering practices.  

Ageing Is Not For the Faint of Heart



Turning off a light is a multi step process. First we must recognize that the light is on, secondly, realize that the light does not need to be on, thirdly realize that it is my responsibility to turn it off, and fourthly to make the decision to turn if off, fifthly summon the volition to make the effort to turn it off, and finally to turn it off. There may also be a requirement to not get distracted through the process, and to remember where the light switch is and why we walked across the room.

Living with someone who cannot put those steps together is an opportunity to practice love, tolerance, compassion, understanding, and a lot of other generally positive characteristics; also overcome some negative feelings, reactions, and characteristics.    

Friday, April 8, 2011

Real or Fiction

What is written on (or should that be in) this blog may be truths or fiction; I do not know. Even intended facts are questionable, as until we know everything about a subject, and do a detailed report, some facts are only approximation of the real truth. Coarse models, if you will accept the concepts of words being only a model of reality. Some fiction is intended, some is not; and is more like errors or beliefs than fiction.

Today, it is my view that gods are just concepts. I was raised with hell fire and damnation religion, so I think they and there beliefs were just fiction as opposed to the view that religious people outright lied to me. Once I realized that gods are just concepts, it allowed me to step back and separate me from my beliefs, and become more objective. I now believe that all beliefs must be reviewed, and the garbage beliefs cleaned out. Some of the beliefs will remain, even when we know they are wrong, or contain both good parts and bad, as we do not know what is better. It is better to replace beliefs with real facts.

Non of this blog should be considered advise, as I am a geotechnical engineer, and not trained in any other field; however, I do read and form opinions, which I will express openly without reservation.

The government intends to mislead us in many areas, mostly for there benefit, nutrition being just one area. It makes decision that are based on opinions of the time which are usually twenty years behind the times, and once something is started, a major correction is near impossible, even when it is badly required. Such is the case with nutrition recommendations. Until the corrections are made, each individual must decide for themselves what is best and who's advice to follow. If you think government nutrition advice is bad, consider that Building Code mess that geotechnical engineers are in in Alberta.