Soil consolidation

Failure of cooling water piping in sequence 17 was dominated by soil consolidation lailure of underground piping. The pipe is subject to non-ductile cracking during extremely cold w eather. 

Failure of the 25 million gallon cooling water basin in sequence 16 was dominated by failure of the Building 186 cooling water reservoir from soil consolidation. 

In terms of dead loads, the shape of the trench in which the pipe will be buried is also a factor. Generally speaking, a narrow trench with vertical sidewalls will impose less of a load on the pipe than will a wider trench with sloping side walls. It is necessary also to know the modulus of soil reaction (E), which is dependent on the type or classification of the native soil, the backfill material that is contemplated, and the desired consolidation of the backfill material. Soil consolidation is important, because it contributes to the strength of a flexible conduit in a buried pipe system. 

Poly(acrylic acid) and its salts have been known to have useful binding properties for some thirty years they have been used for soil consolidation (Lambe Michaels, 1954 Hopkins, 1955 Wilson Crisp, 1977) and as a flocculant (Woodberry, 1961). The most interesting of these applications is the in situ polymerization of calcium acrylate added to soil (de Mello, Hauser Lambe, 1953). But here we are concerned with cements formed from these polyacids. 

Yet another example of natural chemical bonding is solidification of desert soils to build bird houses in Egypt. Nile silt was mixed with desert grass and river water to make tower shapes on concrete roofs (Fig. 1.2). Holes made in these towers provide shelter to the birds, which eventually are sold for food. The minerals from such rich soils consolidate when they are mixed with water and are dried in the intense sun of the desert. 

During the lecture, the author chose a couple of student submissions to present and illustrated to them that the thick soft clay was still consolidating. I further explained why the clay was still very soft and why a very deep excavation in thick soft clay could be problematic. Many students found this helpful to overcome the tedious and abstract topic of soil consolidation. More importantly I found a good number of students became very much interested in geotechnical... 

Applications - brake linings, composites, foundry, mortar cements, refractory materials, sand and soil consolidation, wood modification ... 

Seismic-induced settlement may be caused by densification of cohesionless soils, consolidation of cohesive soils, or consolidation of liquefied soil. In this section we will only discuss liquefaction-induced ground settlement as it can cause larger settlement and hence higher potential for damage to buried pipelines. 

Prefabricated vertical drains providing dewatering until water evacuation and associated soil consolidation occur... 

Gillette, D.A. 1978. A wind-tunnel simulation of the erosion of sod Effect of soil moisture, sandblasting, wind speed and soil consolidation on dust production. Atmospheric Environment 12(8) 1735-1743. 

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