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81-598: The Baldwin Hills Dam disaster occurred on December 14, 1963 (60 years ago)  ( 1963-12-14 ) in the Baldwin Hills neighborhood of South Los Angeles , when the dam containing the Baldwin Hills Reservoir suffered a catastrophic failure and flooded the residential neighborhoods surrounding it. It began with signs of lining failure, followed by increasingly serious leakage through

162-577: A x {\displaystyle e_{max}} is the "maximum void ratio" corresponding to a very loose state, e m i n {\displaystyle e_{min}} is the "minimum void ratio" corresponding to a very dense state and e {\displaystyle e} is the in situ void ratio. Methods used to calculate relative density are defined in ASTM D4254-00(2006). Thus if D r = 100 % {\displaystyle D_{r}=100\%}

243-482: A water shortage for 500,000 people. Some 16,000 people lived in the flooded area. Vigorous rescue efforts averted a greater loss of life. The reservoir was constructed on a low hilltop between 1947 (77 years ago)  ( 1947 ) and 1951 (73 years ago)  ( 1951 ) by the Los Angeles Department of Water and Power , directly on an active fault line , which was subsidiary to

324-510: A catastrophe such as an earthquake, fire, or war, and its failure was a blow to engineering confidence and the subject of many writings and two professional conferences (1972 and 1987, see references). The failure occurred shortly after the death of the authoritative Harvard engineer Karl Terzaghi , whose ideas had long dominated both earth dam engineering and the engineering science of soil mechanics ; Terzaghi had also made significant contributions to understanding subsidence in oilfields. This left

405-430: A mixture of gravel and fine sand, with no coarse sand, the sample may be gap graded . Uniformly graded and gap graded soils are both considered to be poorly graded . There are many methods for measuring particle-size distribution . The two traditional methods are sieve analysis and hydrometer analysis. The size distribution of gravel and sand particles are typically measured using sieve analysis. The formal procedure

486-415: A mixture of particles of different size, shape and mineralogy. Because the size of the particles obviously has a significant effect on the soil behavior, the grain size and grain size distribution are used to classify soils. The grain size distribution describes the relative proportions of particles of various sizes. The grain size is often visualized in a cumulative distribution graph which, for example, plots

567-579: A new technology at the time, was a significant cause of the failure, triggering hydraulic fracturing and aggravating movements on a fault traversing the reservoir even on the day of the failure. Subsequently, the US Geological Survey concluded in 1976 that displacements at the ground surface causing reservoir failure and ground cracking in the Stocker-LaBrea area southeast of the reservoir were 90% or more attributable to exploitation of

648-417: A relatively large specific surface area. The specific surface area (SSA) is defined as the ratio of the surface area of particles to the mass of the particles. Clay minerals typically have specific surface areas in the range of 10 to 1,000 square meters per gram of solid. Due to the large surface area available for chemical, electrostatic, and van der Waals interaction, the mechanical behavior of clay minerals

729-422: A river bed. Wind blown soil deposits ( aeolian soils) also tend to be sorted according to their grain size. Erosion at the base of glaciers is powerful enough to pick up large rocks and boulders as well as soil; soils dropped by melting ice can be a well graded mixture of widely varying particle sizes. Gravity on its own may also carry particles down from the top of a mountain to make a pile of soil and boulders at

810-579: A small but non-negligible amount of fines (5–12%) may be given a dual classification such as SW-SC . Clays and Silts, often called 'fine-grained soils', are classified according to their Atterberg limits ; the most commonly used Atterberg limits are the Liquid Limit (denoted by LL or w l {\displaystyle w_{l}} ), Plastic Limit (denoted by PL or w p {\displaystyle w_{p}} ), and Shrinkage Limit (denoted by SL ). The Liquid Limit

891-414: A soil. As the transitions from one state to another are gradual, the tests have adopted arbitrary definitions to determine the boundaries of the states. The liquid limit is determined by measuring the water content for which a groove closes after 25 blows in a standard test. Alternatively, a fall cone test apparatus may be used to measure the liquid limit. The undrained shear strength of remolded soil at

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972-709: A suspiciously similar major failure of the Bureau of Reclamation's Teton Dam in June 1976, and a near failure of the Department of Water and Power's Lower Van Norman Dam in the 1971 San Fernando earthquake . Professor Ronald Scott of Caltech, who had participated in the Casagrande studies, noted at a follow-up 1987 conference on Baldwin Hills that Casagrande had ignored or been unaware of ground movements clearly unrelated to

1053-630: A time when the pace of dam building was accelerating even as some disastrous dam failures were occurring, indicating a need for safer technologies. The builder of the Baldwin Hills dam, the Los Angeles Department of Water and Power, was aware of the difficult geologic conditions presented by the site and knew from past experiences, notably the catastrophic failure of the St. Francis Dam in 1928 in which over 400 people lost their lives,

1134-419: A variety of parameters used to describe the relative proportions of air, water and solid in a soil. This section defines these parameters and some of their interrelationships. The basic notation is as follows: V a {\displaystyle V_{a}} , V w {\displaystyle V_{w}} , and V s {\displaystyle V_{s}} represent

1215-546: Is quartz , also called silica , which has the chemical name silicon dioxide. The reason that feldspar is most common in rocks but silica is more prevalent in soils is that feldspar is much more soluble than silica. Silt , Sand , and Gravel are basically little pieces of broken rocks . According to the Unified Soil Classification System , silt particle sizes are in the range of 0.002 mm to 0.075 mm and sand particles have sizes in

1296-405: Is a common example of a residual soil. The common mechanisms of transport are the actions of gravity, ice, water, and wind. Wind blown soils include dune sands and loess . Water carries particles of different size depending on the speed of the water, thus soils transported by water are graded according to their size. Silt and clay may settle out in a lake, and gravel and sand collect at the bottom of

1377-546: Is a neighborhood within the South Los Angeles region of Los Angeles , California. Often referred to as the "Black Beverly Hills", Baldwin Hills is home to Kenneth Hahn State Regional Park and to Village Green , a National Historic Landmark . Baldwin Hills and surrounding areas were part of Rancho La Cienega o Paso de la Tijera and later owned by the 19th century L.A. pioneer Elias “Lucky” Baldwin . The Sanchez Adobe de Rancho La Cienega o Paso de la Tijera

1458-543: Is defined as the difference between the Liquid Limit and the Plastic Limit of the specimen; it is an indicator of how much water the soil particles in the specimen can absorb, and correlates with many engineering properties like permeability, compressibility, shear strength and others. Generally, the clay having high plasticity have lower permeability and also they are also difficult to be compacted. According to

1539-417: Is defined as the size for which 10% of the particle mass consists of finer particles. Sands and gravels that possess a wide range of particle sizes with a smooth distribution of particle sizes are called well graded soils. If the soil particles in a sample are predominantly in a relatively narrow range of sizes, the sample is uniformly graded . If a soil sample has distinct gaps in the gradation curve, e.g.,

1620-541: Is described in ASTM D6913-04(2009). A stack of sieves with accurately dimensioned holes between a mesh of wires is used to separate the particles into size bins. A known volume of dried soil, with clods broken down to individual particles, is put into the top of a stack of sieves arranged from coarse to fine. The stack of sieves is shaken for a standard period of time so that the particles are sorted into size bins. This method works reasonably well for particles in

1701-413: Is determined primarily by their Atterberg limits , not by their grain size. If it is important to determine the grain size distribution of fine-grained soils, the hydrometer test may be performed. In the hydrometer tests, the soil particles are mixed with water and shaken to produce a dilute suspension in a glass cylinder, and then the cylinder is left to sit. A hydrometer is used to measure the density of

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1782-892: Is primarily derived from friction between the particles and interlocking, which are very sensitive to the effective stress. The article concludes with some examples of applications of the principles of soil mechanics such as slope stability, lateral earth pressure on retaining walls, and bearing capacity of foundations. The primary mechanism of soil creation is the weathering of rock. All rock types ( igneous rock , metamorphic rock and sedimentary rock ) may be broken down into small particles to create soil. Weathering mechanisms are physical weathering, chemical weathering, and biological weathering Human activities such as excavation, blasting, and waste disposal, may also create soil. Over geologic time, deeply buried soils may be altered by pressure and temperature to become metamorphic or sedimentary rock, and if melted and solidified again, they would complete

1863-470: Is served by Los Angeles Unified School District . Baldwin Hills also has a charter school. The schools operating within Baldwin Hills borders are: New LA Elementary School, a charter school , is on the grounds of Baldwin Hills Elementary. A California law called Proposition 39 allows New LA to occupy space on the grounds of Baldwin Hills Elementary. In 2022, area community members advocated for

1944-474: Is the ratio of the volume of voids to the volume of solids: Porosity , n {\displaystyle n} , is the ratio of volume of voids to the total volume, and is related to the void ratio: Degree of saturation , S {\displaystyle S} , is the ratio of the volume of water to the volume of voids: From the above definitions, some useful relationships can be derived by use of basic algebra. Geotechnical engineers classify

2025-405: Is the water content at which the soil behavior transitions from a plastic solid to a liquid. The Plastic Limit is the water content at which the soil behavior transitions from that of a plastic solid to a brittle solid. The Shrinkage Limit corresponds to a water content below which the soil will not shrink as it dries. The consistency of fine grained soil varies in proportional to the water content in

2106-412: Is very sensitive to the amount of pore fluid available and the type and amount of dissolved ions in the pore fluid. The minerals of soils are predominantly formed by atoms of oxygen, silicon, hydrogen, and aluminum, organized in various crystalline forms. These elements along with calcium, sodium, potassium, magnesium, and carbon constitute over 99 per cent of the solid mass of soils. Soils consist of

2187-567: The Inglewood Oil Field and ground disturbances in the area, including beneath the reservoir and at some distance from the reservoir—concluded rather vaguely that the failure was due to "an unfortunate combination of physical factors". The monetary damages resulting from the failure were large, and some of the investigations that followed the state study were sponsored by litigants seeking more specific conclusions relevant to legal liability. This drew attention to oilfield operations in

2268-599: The Kenneth Hahn State Recreation Area . A plaque was placed at the site on the 50th anniversary of the disaster in 2013. The five fatalities were Hattie Schwartz, Maurice Clifton Carroll, Arch Young, Orra G. Strathearn, and Archie V. MacDonald. The failure of the Baldwin Hills Reservoir received an exceptional amount of attention from the civil engineering community and remains the subject of continuing interest. The reservoir had been conceived, designed, and built during and after World War II,

2349-481: The Los Angeles Department of Water and Power to close and drain other small local reservoirs with similar designs, such as the Silver Lake Reservoir . The Baldwin Hills Dam was not rebuilt—instead, the empty reservoir was demolished, filled with earth, landscaped, and converted to Kenneth Hahn Regional Park . During the summer of 1985, a brush fire along La Brea Avenue spread up the canyon towards

2430-480: The Unified Soil Classification System (USCS), silts and clays are classified by plotting the values of their plasticity index and liquid limit on a plasticity chart. The A-Line on the chart separates clays (given the USCS symbol C ) from silts (given the symbol M ). LL=50% separates high plasticity soils (given the modifier symbol H ) from low plasticity soils (given the modifier symbol L ). A soil that plots above

2511-497: The Unified Soil Classification System , a #4 sieve (4 openings per inch) having 4.75 mm opening size separates sand from gravel and a #200 sieve with an 0.075 mm opening separates sand from silt and clay. According to the British standard, 0.063 mm is the boundary between sand and silt, and 2 mm is the boundary between sand and gravel. The classification of fine-grained soils, i.e., soils that are finer than sand,

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2592-546: The "$ 30 million Crenshaw-Santa Barbara Shopping Center. On December 14, 1963, a crack appeared in the Baldwin Hills Dam impounding the Baldwin Hills Reservoir . Within a few hours, water rushing through the crack eroded the earthen dam, gradually widening the crack until the dam failed catastrophically at 3:38 p.m. When the crack was discovered, police with bullhorns urged the evacuation of

2673-424: The 1964 DWR failure study implied that heavy compaction was a favored technique for earth dam construction, and this assumption appeared not to have been reexamined over the 25 years of post-failure investigation and discussion. The failure of the reservoir has been a subject of ongoing interest in the field of dam-breach studies. A recent study examined the dam failure as a two-stage process and succeeded in modeling

2754-419: The 1964 state investigation, took on a role as neutral reviewer in this and most subsequent American studies of the failure. Leps concluded that about 7 inches of offset had occurred on the fault beneath the reservoir during its life, about 2 inches of which had occurred in the months just before the failure. Leps associated the latter with repressurization of the oilfield. This, along with stretching of

2835-538: The A-line and has LL>50% would, for example, be classified as CH . Other possible classifications of silts and clays are ML , CL and MH . If the Atterberg limits plot in the"hatched" region on the graph near the origin, the soils are given the dual classification 'CL-ML'. The effects of the water content on the strength of saturated remolded soils can be quantified by the use of the liquidity index , LI : When

2916-440: The Baldwin Hills may also be related to raised pressures resulting from injection, and may be of similar origin as the gas problems in the nearby Salt Lake field. KTLA used a helicopter to cover the disaster. Richard N. Levine, a 17-year-old photography student, rushed to a higher viewpoint and made 35-mm pictures of the evolving dam break. Notes Bibliography Baldwin Hills, Los Angeles, California Baldwin Hills

2997-490: The Inglewood oil field, and that this faulting was likely aggravated by water flooding with pressures exceeding hydraulic fracturing levels. By 1972, nearly a decade after the failure, the immediate legal issues had been settled out of court and the matter was reopened as a topic of discussion among investigators in a published engineering conference at Purdue University. Engineer Thomas Leps, who had served as consultant on

3078-446: The LI is 1, remolded soil is at the liquid limit and it has an undrained shear strength of about 2 kPa. When the soil is at the plastic limit , the LI is 0 and the undrained shear strength is about 200 kPa. The density of sands (cohesionless soils) is often characterized by the relative density, D r {\displaystyle D_{r}} where: e m

3159-452: The Los Angeles Department of Water and Power on the failed St. Francis Dam, and had subsequently devised new methods of producing compacted earth fill in building its replacement. Proctor aggressively proceeded with the Baldwin Hills project even in the face of safety concerns and disagreements over important design details raised within his own department. Late in 1963, when the Baldwin Hills failure occurred, coincidentally also happened to be

3240-474: The US Geological Survey in 1969. Subsidence following oil extraction from shallow deposits in unconsolidated sediments had been understood by oil industry experts since the 1920s. Following the discovery in 1970 by geologist Douglas Hamilton of faulting and surface seepage of oilfield waste brines along the fault, which traversed and extended south of the reservoir, Hamilton and Meehan concluded that oilfield injection for waste disposal and improved recovery of oil,

3321-429: The USCS, gravels (given the symbol G ) and sands (given the symbol S ) are classified according to their grain size distribution. For the USCS, gravels may be given the classification symbol GW (well-graded gravel), GP (poorly graded gravel), GM (gravel with a large amount of silt), or GC (gravel with a large amount of clay). Likewise sands may be classified as being SW , SP , SM or SC . Sands and gravels with

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3402-457: The area, but six people were killed. Two hundred homes were completely wiped out, and an additional 1500 to 2000 houses and apartment buildings were damaged, and most of Baldwin Vista and the historic Village Green community were flooded. The dam's failure was ultimately determined to be the result of subsidence , caused by overexploitation of the Inglewood Oil Field . The dam's failure prompted

3483-412: The area. From the outset, the ground faulting and fault creep which destroyed the reservoir were probably related to the many feet of ground subsidence that had occurred a half mile west of the reservoir over decades of oil extraction in the Inglewood field. The oilfield-related subsidence in the Inglewood field, though generally denied by the oil companies as a legal policy, was documented exhaustively by

3564-614: The arrangement of particles in a load carrying framework as well as the pore size and pore fluid distributions. Engineering geologists also classify soils based on their genesis and depositional history. In the US and other countries, the Unified Soil Classification System (USCS) is often used for soil classification. Other classification systems include the British Standard BS 5930 and the AASHTO soil classification system. In

3645-491: The assessment of the Baldwin Hills failure in the hands of a new generation of engineers, some of whom took on conflicting roles as experts in various lawsuits. The design and construction of the dam had been inspected and approved by the California Department of Water Resources. A meticulously documented study published by that agency in 1964—while pointing out various connections between oilfield operations in

3726-420: The base; soil deposits transported by gravity are called colluvium . The mechanism of transport also has a major effect on the particle shape. For example, low velocity grinding in a river bed will produce rounded particles. Freshly fractured colluvium particles often have a very angular shape. Silts, sands and gravels are classified by their size, and hence they may consist of a variety of minerals. Owing to

3807-464: The character of the compacted earth lining (which had been regularly referred to as clay, but must have been substantially silt and sand, having been derived from the local Inglewood formation) was raised, if obliquely, in the suggestion made in the end that improved performance might have come from the use of a different lining material. In 2001, a new angle on failure analysis was introduced by Mahunthan and Schofield, who concluded that overcompaction of

3888-628: The charter school to move to another location since they believed that it meant there would not be enough space for the public elementary to operate efficiently. Soil mechanics Soil mechanics is a branch of soil physics and applied mechanics that describes the behavior of soils . It differs from fluid mechanics and solid mechanics in the sense that soils consist of a heterogeneous mixture of fluids (usually air and water) and particles (usually clay , silt , sand , and gravel ) but soil may also contain organic solids and other matter. Along with rock mechanics , soil mechanics provides

3969-487: The dam and reservoir being the significant cause of the fatal foundation movement. This view exonerated the oil companies, namely Standard Oil, which had sponsored the study. Casagrande refused to acknowledge any ground movements in the area as being related to oilfield operations and argued that ground movements that affected the dam were found only beneath the reservoir, not in adjoining areas. Most of these questions were examined once again in 1986 following investigations of

4050-399: The dam at its east abutment. After three hours, the dam breached, and "it took only 77 minutes for all the water to pour out into Cloverdale Avenue, La Brea Avenue , La Cienega and Jefferson Boulevard ." The collapse resulted in a release of 290 million US gallons (1,100,000 m), causing five deaths and the destruction of 277 homes. Damage totaled $ 12 million and the disaster caused

4131-545: The dam fill and lining was a significant aggravating factor in both the Baldwin Hills and Teton failures. This assertion was based on Schofield's concepts of critical-state soil mechanics, a corollary of which was that heavily compacted but lightly confined soils could be dangerously unstable where seepage forces were present. This issue had not been raised in the previous American-dominated discussions and remains in some degree contrary to American ideas in both theoretical soil mechanics and practical geotechnical engineering. In fact,

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4212-525: The density of the mixture minus the density of water is useful if the soil is submerged under water: where ρ w {\displaystyle \rho _{w}} is the density of water Water Content , w {\displaystyle w} is the ratio of mass of water to mass of solid. It is easily measured by weighing a sample of the soil, drying it out in an oven and re-weighing. Standard procedures are described by ASTM. Void ratio , e {\displaystyle e} ,

4293-462: The density of the mixture, i.e., the total mass of air, water, solids divided by the total volume of air water and solids (the mass of air is assumed to be zero for practical purposes): Dry Density , ρ d {\displaystyle \rho _{d}} , is the mass of solids divided by the total volume of air water and solids: Buoyant Density , ρ ′ {\displaystyle \rho '} , defined as

4374-585: The flood in the urban area downstream. Although the Baldwin Hills Reservoir site has now been dedicated as a community park, and no further significant hazard is associated with ground movements there, the associated faults to the southeast (Stocker-LaBrea and the Windsor School area) continue to move significantly as of 2012, causing damage to private and public facilities. The current oilfield operator, Plains Exploration and Production Company (PXP), which has intensified production and development efforts in

4455-408: The genesis and composition of soil, the distinction between pore water pressure and inter-granular effective stress , capillary action of fluids in the soil pore spaces, soil classification , seepage and permeability , time dependent change of volume due to squeezing water out of tiny pore spaces, also known as consolidation , shear strength and stiffness of soils. The shear strength of soils

4536-475: The geologic cycle by becoming igneous rock. Physical weathering includes temperature effects, freeze and thaw of water in cracks, rain, wind, impact and other mechanisms. Chemical weathering includes dissolution of matter composing a rock and precipitation in the form of another mineral. Clay minerals, for example can be formed by weathering of feldspar , which is the most common mineral present in igneous rock. The most common mineral constituent of silt and sand

4617-404: The ground due to subsidence of about 12 feet from oil extraction, had caused the lining failure that doomed the reservoir. Some prominent consultants, including those on a team led by Arthur Casagrande, Harvard successor to Karl Terzaghi, held that oilfield operations were not a significant influence at all, but that the failure was the result of defective siting and design with the heavy weight of

4698-708: The homes along Don Carlos Drive in Baldwin Hills Estates. Many homes were destroyed despite the efforts of the Los Angeles Fire Department to suppress the flames. The fire killed three people and destroyed 69 homes; the arsonist was never caught. In 1985, the Los Angeles Times noted that Baldwin Hills is "now often called the Black Beverly Hills". Baldwin Hills is bounded by La Cienega Boulevard to

4779-414: The liquid limit is approximately 2 kPa. The Plastic Limit is the water content below which it is not possible to roll by hand the soil into 3 mm diameter cylinders. The soil cracks or breaks up as it is rolled down to this diameter. Remolded soil at the plastic limit is quite stiff, having an undrained shear strength of the order of about 200 kPa. The Plasticity Index of a particular soil specimen

4860-641: The mass, M, by the acceleration due to gravity, g; e.g., W s = M s g {\displaystyle W_{s}=M_{s}g} Specific Gravity is the ratio of the density of one material compared to the density of pure water ( ρ w = 1 g / c m 3 {\displaystyle \rho _{w}=1g/cm^{3}} ). Specific gravity of solids , G s = ρ s ρ w {\displaystyle G_{s}={\frac {\rho _{s}}{\rho _{w}}}} Note that specific weight , conventionally denoted by

4941-433: The masses of air, water and solids in a soil mixture; ρ a {\displaystyle \rho _{a}} , ρ w {\displaystyle \rho _{w}} , and ρ s {\displaystyle \rho _{s}} represent the densities of the constituents (air, water and solids) in a soil mixture; Note that the weights, W, can be obtained by multiplying

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5022-463: The oilfield with the rising price of petroleum, does not, unlike its predecessor Standard Oil, acknowledge any causal connection between fault movements and oilfield activities, and has retained a team of consultants who support this position or conclude that the causes of the movements are unknown. The role of shallow hydraulic fracturing , which has recently been introduced as a means of stimulating production at depths around 2,000 feet (600 m) in

5103-454: The percentage of particles finer than a given size as a function of size. The median grain size, D 50 {\displaystyle D_{50}} , is the size for which 50% of the particle mass consists of finer particles. Soil behavior, especially the hydraulic conductivity , tends to be dominated by the smaller particles, hence, the term "effective size", denoted by D 10 {\displaystyle D_{10}} ,

5184-447: The range of 0.075 mm to 4.75 mm. Gravel particles are broken pieces of rock in the size range 4.75 mm to 100 mm. Particles larger than gravel are called cobbles and boulders. Soil deposits are affected by the mechanism of transport and deposition to their location. Soils that are not transported are called residual soils —they exist at the same location as the rock from which they were generated. Decomposed granite

5265-422: The reservoir (e.g. those at Stocker-LaBrea) in his analysis. Another engineer, Stanley Wilson—who had also worked with Casagrande on the 1972 studies and supported the claim that oilfield subsidence was an insignificant cause—now conceded that analogous ground offsets extended well outside the reservoir area, notably in the Stocker-LaBrea area, so that the reservoir and other fault movements could not be attributed to

5346-405: The reservoir itself—thus tacitly attributing responsibility for the failure to oilfield operations. Hence, the opinions on the role of oilfield subsidence and repressurization appeared to converge. The issue of oilfield causation was a central theme in most of these discussions, with little attention having been directed to the details of the failure. The absolute necessity of a lining for this site

5427-401: The sand and gravel size range. Fine particles tend to stick to each other, and hence the sieving process is not an effective method. If there are a lot of fines (silt and clay) present in the soil it may be necessary to run water through the sieves to wash the coarse particles and clods through. A variety of sieve sizes are available. The boundary between sand and silt is arbitrary. According to

5508-467: The serious consequences of a failure, even of a small reservoir in an urban setting. While dams were recognized as potentially dangerous, like nuclear technologies, they were also considered by Americans as a showcase technology—a means of fending off danger and spreading progressive American technologies and associated social benefits at home and abroad. The Baldwin Hills dam designer, engineer Ralph Proctor, had also worked as an assistant civil engineer for

5589-409: The soil particle types by performing tests on disturbed (dried, passed through sieves, and remolded) samples of the soil. This provides information about the characteristics of the soil grains themselves. Classification of the types of grains present in a soil does not account for important effects of the structure or fabric of the soil, terms that describe compactness of the particles and patterns in

5670-498: The southeast part of the Inglewood field, and at greater depths elsewhere in the field, has also generated public concern and controversy. However, oil operators, while admitting that fracture pressures are being exceeded, refuse to acknowledge a relationship between injection at fracturing pressure levels and fault movement. The PXP and PXP consultant conclusions, that adverse effects are either unknown or not present, are disputed by other reviewers. Recent discharges of oilfield gases in

5751-584: The stability of quartz compared to other rock minerals, quartz is the most common constituent of sand and silt. Mica, and feldspar are other common minerals present in sands and silts. The mineral constituents of gravel may be more similar to that of the parent rock. The common clay minerals are montmorillonite or smectite , illite , and kaolinite or kaolin. These minerals tend to form in sheet or plate like structures, with length typically ranging between 10  m and 4x10  m and thickness typically ranging between 10  m and 2x10  m, and they have

5832-624: The suspension as a function of time. Clay particles may take several hours to settle past the depth of measurement of the hydrometer. Sand particles may take less than a second. Stokes' law provides the theoretical basis to calculate the relationship between sedimentation velocity and particle size. ASTM provides the detailed procedures for performing the Hydrometer test. Clay particles can be sufficiently small that they never settle because they are kept in suspension by Brownian motion , in which case they may be classified as colloids . There are

5913-406: The symbol γ {\displaystyle \gamma } may be obtained by multiplying the density ( ρ {\displaystyle \rho } ) of a material by the acceleration due to gravity, g {\displaystyle g} . Density , Bulk Density , or Wet Density , ρ {\displaystyle \rho } , are different names for

5994-659: The theoretical basis for analysis in geotechnical engineering , a subdiscipline of civil engineering , and engineering geology , a subdiscipline of geology . Soil mechanics is used to analyze the deformations of and flow of fluids within natural and man-made structures that are supported on or made of soil, or structures that are buried in soils. Example applications are building and bridge foundations, retaining walls, dams, and buried pipeline systems. Principles of soil mechanics are also used in related disciplines such as geophysical engineering , coastal engineering , agricultural engineering , and hydrology . This article describes

6075-580: The time of another notable public disaster. Only two months before, at the Vajont Dam in Italy, a massive landslide into the reservoir created a seiche , which overtopped the dam, thereby flooding the valley below and causing the deaths of about 2000 people. The Baldwin Hills Reservoir had been built, as were others, to assure an ample supply of safe water for the people of Los Angeles in case of

6156-592: The village consisted of several hundred buildings, including post and telegraph offices, an amphitheater , a hospital, a fire department, and a bank. Female athletes were housed at the Chapman Park Hotel on Wilshire Boulevard. The Olympic Village was demolished after the Summer Olympic Games . In 1950, new homes in Baldwin Hills were designed by Paul W. Trousdale & Associates (of Trousdale Estates fame) and advertised as being near

6237-525: The volumes of air, water and solids in a soil mixture; W a {\displaystyle W_{a}} , W w {\displaystyle W_{w}} , and W s {\displaystyle W_{s}} represent the weights of air, water and solids in a soil mixture; M a {\displaystyle M_{a}} , M w {\displaystyle M_{w}} , and M s {\displaystyle M_{s}} represent

6318-408: The well-known nearby Newport–Inglewood Fault . The underlying geologic strata were considered unstable for a reservoir, and the design called for a compacted soil lining meant to prevent seepage into the foundation. The fault lines were considered during planning, but were deemed by some, although not all, of the engineers and geologists involved as not significant. The former reservoir is now part of

6399-534: The west, Crenshaw Boulevard to the east, Stocker Street to the south and Obama Boulevard to the north with Martin Luther King Jr. Boulevard forming the northeast dividing line between Baldwin Hills and Crenshaw Manor . It is bordered on the west by Culver City and it shares the eastern border of Crenshaw Boulevard with Leimert Park . The namesake mountain range is part of the neighborhood. Neighborhoods within Baldwin Hills include: Baldwin Hills

6480-406: Was generally taken for granted in these proceedings even as it had been by Proctor himself, regardless of the fact that almost all earth dams perform satisfactorily without linings. Some suggestions as to possible preventive design and construction techniques that might have made the dam safer were raised to engineering consensus and reached a state of textbook knowledge in the late 1980s. For example,

6561-545: Was once the center of the rancho. In the 1920s, an addition was built linking the structures and the building was converted into a larger clubhouse for the Sunset Golf Course. The 1932 Los Angeles Olympics housed athletes at the Olympic Village in Baldwin Hills. It was the site of the very first Olympic Village ever built, for the 1932 Los Angeles Summer Olympic Games . Built for male athletes only,

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