First use of drilled horizointal drains [hydraugers] (1939)
Hydarugers, or horizontal drains, were first employed in 1939 by the The California Division of Highways, described in “Horizontal Drains on California Highways” by T.W. Smith and G.V. Stafford in the July 1957 ASCE Journal of the Soil Mechanics and Foundations Division. Similar concepts were developed in 1940 by Earl M. Buckingham, PE (1902-97), Supervising Civil Engineer for Oakland, working with the Ransome Construction Company (est by E.L. Ransome in 1870, and still operating out of San Leandro), the first private venture to employ similar technology. Ransome developed a drilling machine that utilized a reversible air motor with a hollow crankshaft which delivered watter to the rotating cutting bit through a string of hollow rods. They were often used in combination with vertical relief wells, as part of slope stabilization schemes. Some of the early stabilization projects included the McKillop Road and Simmons Street Lanslides (1940), the Barrows-Holman Roads Slide (1942), and Underhills Road slide (1943), all in the City of Oakland (described in Hyde Forbes’ 1947 article Landslide Investigation and Correction, cited below). During the Second World War they were obliged to use peforated aluminum casings because steel was not readily available.
The original approach was to use modified fishtail bits drilling 4-inch diameter holes, within which would be inserted 2-inch diameter steel pipe with 3/8th-inch diameter perforations. The perforated casing came in lengths between 16 and 24 feet. In 1949 the industry began shifting to the use of rock roller bits used in the petoleum industry because these were readily available in a large variety of diameters. The industry came to call horizontal drains “hydraugers,” a moniker that was subsequently adopted by most agencies that employ them.
Adoption of the Standard Proctor Compaction test by AASHO (1939) and ASTM (1942)
The Standard Proctor Compaction Test was adopted with slight modifications by the American Association of State Highway Officials (AASHO) as the Impact Compaction Test, and assigned Test Designation T-99 in 1939. The Modified Proctor Compaction Test was designed as AASHO Test Designation T-180 in 1946 (described below).
In 1942 the American Society for Testing and Materials (ASTM) approved the same proceedure as their “Tentative Methods of Test for Moisture-Density Relations of Soils” as ASTM Test Standard D 698 in 1942. This profcedure assumed a compactive effort derived from dropping a 5.5 lb weight from a height of 12 inches, engendering a compactive effort of 12,400 ft-lbs input energy per cubic foot of soil. In June 1957 ASTM approved revisions that introduced Methods A, B, C, and D to the standard. Methods B and D allowed the use of 6-inch diameter molds, while Methods C and D allowed the inclusion of particles up to ¾-inches in diameter. The D 698 test proceedures were also revised in Oct 1978 (introduced option for 25 or 56 blows), Nov 1991 (manual versus mechanical rammers), and January 1997 (correction of Eqn 1 to ascertain dry unit weight).
Committee on Soil Mechanics and Foundations of the Los Angeles Section, ASCE (1940)
A special committee on Soil Mechanics and Foundations was formed in 1940 under the chairmanship of SCE Chief Engineer Harry W. Dennis (BSCE 1899 Cornell; also Vice President of ASCE in 1936-37) to cooperate with, and provide input to, the Soil Mechanics and Foundations Division of ASCE established around 1935. The newly formed national division was gathering data from across the country on nine topics: settlement of structures, lateral earth pressures, observed settlement of structures outside the US, properties of clay-type soils, lateral stability of sheeting and piles, properties of “quick sands,” stability of earth dams, problems with sand boils, and seepage effects on stability of earth embankments. This effort was funded by The Engineering Foundation between 1935-49. The local group consisted of 40 members of the Los Angeles Section and they committed themselves to providing whatever geotechnical data they had on the nine subject areas and sponsoring at least one program each year that focused solely on soil mechanics and foundations issues.
By 1944 the officers overseeing this Soil Mechanics Committee were Trent R. Dames, Chairman, Caltech Prof. Frederick J. Converse, Sterling S. Green, and Paul Baumann. By 1946 the Los Angeles Section of ASCE sported 1,350 members, making it the second largest section in the society.
First textbooks on soil mechanics in English: Plummer and Dore (1940); Krynine (1941) and Terzaghi (1943)
In 1940 Fred L. Plummer, Chief Research Engineer for the Hammond Iron Works in Warren, PA, and Stanley M. Dore, Assistant Chielf Engineer for the Metropolitan District Water Suppy Commisison of Massachusetts, co-authored the first textbook in English on soil mechanics in the United States, titled “Soil Mechanics and Foundations,” released by the Pittman Publishing. This text was used in many eastern colleges during the early 1940s, including The Citadel. It included a fairly comprehensive overview of embankment dam engineering practice in the United States up until that time.
In 1941 Dimitri P. Krynine (1877-1967), Research Associate in Soil Mechanics at Yale University, published the second English textbook titled “Soil Mechanics,” released by McGraw-Hill Book Co. Krynine had immigrated to the United States from Russia in February 1930, and became a naturalized American citizen in September 1935. This text went through 11 printings, and was used extensively in the training of both Navy and Army combat engineering officers during the Second World War. Krynine became a Lecturer in Civil Engineering at Yale and released a Second Edition of the textbook in 1947. In 1957 he and William R. Judd of the Bureau of Reclamation co-authored the text Principles of Engineering Geology and Geotechnics, also published by McGraw-Hill. Krynine retired from Yale in 1947, and moved to Alameda, CA (his son Paul Dimitri Krynine who had attended Cal Berkeley in the late 1920s and was a Professor of Geology at Yale and Penn State). Krynine continued consulting to Woodward Clyde in Oakland until he passed away in 1967, at the age of 90.
In early 1936 Professor Karl Terzaghi (1883-1963) at the Technical University in Vienna began preparing the manuscript of a new textbook on soil mechanics in English. This was in anticipation of his involvement in the First International Conference on Soil Mechanics and Foundation Engineering held at Cambridge, MA in June 1936. Terzaghi had hoped this would open up opportunities for him to return to the United States as a professor, but the Great Depression prevented any meangingful offers. He returned to the United States in September 1938 and was given the title of Lecturer in Engineering Geology at Harvard. He continued working on his book manuscript, assisted by a post-graduate student named Ralph Peck, who checked Terzaghi’s English and drafted many of the ink figures. This collaboration resulted in therealse of Terzaghi’s first book in Engish, titled “Theoretical Soil Mechanics, released by John Wiley & Sons in 1943, during the Second World War. It quickly became one of the longest selling titles in John Wiley’s line of textbooks, which remained in-print until 1967.
War Department maps (1941-45)
During the Second World War (1941-45) the U.S. War Department Army Map Service produced a series of 1:20,000 scale topographic maps along the coast of California. These included Special Maps, Battle Maps and Photo Maps. The 6-minute sheets covering Los Angeles County were reproduced by the Army’s 30th Engineering Regiment, on a scale of 1:20,000, slightly larger than their USGS 1:24,000 release scale. The War Department’s 15-minute quads were the first to cover all of Riverside, Imperial and San Diego Counties, because of the military maneuvers carried out in the desert areas in 1942-43 (D.V. Prose, 1985, Map showing areas of visible land disturbances caused by two military training operations in the Mojave Desert, CA: USGS Map MF1855; also see USGS OFR 85-234).
Los Angeles Building Code (1943)
Following the 1933 Long Beach Earthquake, a committee was set up by the Structural Engineers Association of Southern California to develop the first seismic provisions to be put into practice, which was published in the 1943 Los Angeles Building Code. That same year (1943) the State Division of Highways adopted their first seismic lateral design standard, specifying that state bridges in seismically-prone areas should be designed for a lateral pseudo static coefficient of 0.08g. This was employed in state highway work until 1966, when the lessons of the Great Alaska earthquake of March 1964 became more universally appreciated. San Francisco followed suit in 1948, with the adoption of their own building code.
Corps of Engineers Airfield Pavement Design Advisory Council (1942-45)
In June 1941 the Los Angeles District of the U.S. Army Corps of Engineers began wrestling with pavement bearing failures beneath the massive 96-inch diameter tires of the new Douglas B-19 bomber, which weighed 162,000 lbs., spread on just three wheels. The aircraft had cased pavement distress at Clover Field in Santa Monica (where it was built) and at March Army Airfield in Riverside (where it was delivered to the Army Air Corps).
District engineers in Los Angeles quickly consulted with research engineers at the Corps’ Waterways Experiment Station in Vicksburg, MS and it was agreed that an Airfield Pavement Design Advisory Council should be formed, centered around O. James Porter (formerly of the California Division of Highways in Sacramento) because of his pioneering role in developing the California Bearing Ratio Test in 1928 (described previously). The advisory council was comprised of Colonel Henry C. Wolfe (who had worked on the Fort Peck Dam soil mechanics problems), structures Professor Harald M. Westergaard of Harvard, and Dr. Philip C. Rutledge of Moran, Proctor, Freeman & Meuser, soil mechanics Professor Arthur Casagrande of Harvard, Thomas A. Middlebrooks (the Corps senior expert in soil mechanics, who had also worked on the Fort Peck Dam landslide), James L. Land of the Alabama State Highway Department, and O. James Porter of O.J. Porter & Co. of Sacramento.
Through Porter’s urging the advisory council selected the “Stockton Test Track” at the Air Corps’ Stockton Field, about 60 miles south of Sacramento, for the most ambitious field pavement test program ever devised, up to that time. The tests employed a 240,000 lb pneumatic roller passing over pavement sections of varying thickness, stiffness, and consistency, to better evaluate the California Bearing ratio test results for wheel loads of as much as 150,000 pounds.
From these tests, the Army Corps of Engineers developed specialized design procedures for flexible asphalt runways that incorporated the properties of the pavement subgrade, because the aircraft wheel loads are transmitted directly to the subgrade in flexible pavements. This focused attention on the importance of subgrade compaction, leading to the Modified Proctor Compaction Test of 1946 (described below). These design procedures were subsequently incorporated into post-war design of flexible asphalt highway pavements, which were used in the Interstate & Defense Highway Program, beginning in 1955.
Adoption of the Modified Proctor Compaction Test (1946 to 1985)
In 1938-40 Thomas E. Stanton (BSCE 1904 Berkeley) of the California Division of Highways wrote two important papers on mechanical compaction of soil embankments: “Compaction of Earth Embankments” for the Proceedings of the Highway Research Board in 1938, and “Methods of Controlling Compaction in Embankments,“ for the Proceedings of the 1940 AASHO Meeting in Seattle. In this second article he describes a “Modified Proctor Test,” which sought to “obtain higher compacted densities and thus a lower optimum moisture content” than that employed in the “Standard Proctor Test.” Given the fact that Stanton was O.J. “Pappy” Porter’s supervisor, the description of compaction test employing considerably more input energy was therein coined formally in 1946 by Porter as the “modified Proctor basis” of 1946 (see “Soil Compaction for Airports” in Engineering News Record, March 21, 1946, p.82-86).
The “modified Proctor basis” formally endorsed by the Embankment, Foundation, and Pavement Division of the Corps of Engineers Waterways Experiment Station in Vicksburg in 1946 as a “dynamic compaction test,” using the same sort of impact hammer suggested by Proctor in 1933. This was based on input from their Airfield Pavement Design Advisory Council, described above. It employed the same cylindrical mold as the Standard Proctor test (4 inches in diameter and 4.6 inches high, with a removable mold collar 2.5 in. high). The mold volume is 1/30th cubic foot, but it employs a heavier 10-pound hammer, 2 inches in diameter, which is allowed to free-fall 18 inches onto the soil (15 ft-lbs per blow). The soil mixture is compacted in five lifts, with an average thickness of 0.80 inches/lift. 25 blows were exerted per lift, which equals 25 x 15 = 375 ft-lbs per lift. The total input energy for the five lifts is 5 x 375 = 1875 ft-lbs on a soil sample with a volume of 1/30th cubic foot. This equals 56,250 ft-lbs of compactive energy per cubic foot of soil, about 450% more energy than the Standard Proctor procedure.
By 1950 the Corps of Engineers issued reports which suggested that cohesionless soils (e.g. aggregate subbase and aggregate baserock) should be compacted “in a saturated state with the modified AASHO compactive effort” (see Waterways Experiment Station,” Soil Compaction Investigation Report No 5, “Miscellaneous Laboratory Tests,” Technical Memorandum No. 3-271, Vicksburg, June 1950). The new test was designated as Modified AASHTO T180 (adopted in 1946), while the ASTM Test Standard D 1557 was not adopted until 1958. Though originally developed for airfield runways and pavement subgrades, the Modified Proctor Test become the national standard by 1985, when UBC Test 70-1 (33,800 ft-lbs/ft3 input energy) was discarded by the UBC Appendix Chapter 70, in favor of ASTM D 1557.
Engineering Geology Division of GSA (1947)
The Engineering Geology Division (EGD) of the Geological Society of America was established as that society’s first specialty division in 1947, in contrast to the Society’s established geographic sections. This came about because of the widespread use and organization of engineering geologists and military geologists by federal agencies during the Second World War (1939-45). Prof. Charles P. Berkey of Columbia University served as the division’s first chairman, Sidney Paige as vice-chairman, and Roger Rhoades, secretary. Other geologists who figured prominently in the establishment of the new division included: Arthur B. Cleaves, Parker D. Trask, Edward Burwell, William Irwin, Shailer Philbrick, and George Woollard.
In 1951 one of the earliest definitions of "Engineering Geologist" or "Professional Engineering Geologist" was provided by the Executive Committee of the EGD, as follows: “A professional engineering geologist is a person who, by reason of his special knowledge of the geological sciences and the principles and methods of engineering analysis and design acquired by professional education or practical experience, is qualified to apply such special knowledge for the purpose of rendering professional services or accomplishing creative work such as consultation, investigation, planning, design or supervision of construction for the purpose of assuring that the geologic elements affecting the structures, works or projects are adequately treated by the responsible engineer.” These concepts and definitions were absorbed into the certifications by the City of Los Angeles (1958), Los Angeles County (1960), Orange County (1962), AIPG (1963), and the State of California (1969), described below.
The EGD began publishing a quarterly newsletter titled The Engineering Geologist in April 1966, with Prof. Dick Goodman at Berkeley serving as the newletter’s first editor. The division was re-named the Environmental & Engineering Geology Division of GSA in 2011, to better reflect the evolving focus of applied geology in the 21st Century.
USGS 7.5-minute quadrangles (1947-95)
Shortly after the Second World War the USGS began to photograph all of the continental United States to develop 7.5 minute (1:24,000 scale) maps of urban areas and complete their 15-minute (1:62,500 scale) of mountainous and/or uninhabited areas, using orthophoto-derived techniques (most commonly, Zeiss Stereoscopes). These photos were imaged between 1946-49, and the initial series of 7.5-min. maps were released between 1947-59. Less inhabited regions, such as the Diablo Range, were covered by the larger scale 15-minute maps.
In 1956 the USGS began imaging a second series of aerial photos across California, part of a program then envisioned library photography on 10-year intervals. A second series of 7.5 minute maps began to be released, beginning in 1959, based on this new imagery. These second generation maps were only produced in areas where urban growth was rapidly expanding, such as the East Bay. These maps were released between 1956-79. Contour intervals were generally 20 or 40 feet on the 7.5 minute series maps and 40 or 80 feet on the 15 minute series.
In the early 1970s the USGS committed to mapping all of California on 7.5 minute 1:24,000 scale maps, and this program was completed around 1987. Digital map overlays are now provided for areas of large urban growth by using gray shadowing, without benefit of replicating the newly-created topography. These overlay updates are electronically generated from space-based imagery. Funding for USGS mapping activities was severely curtailed during the 94th Congress in 1995, and no new topographic map products are currently contemplated other than shadow overlays delineating newly developed areas. In 1996 Wildflower Productions began releasing USGS 7.5 min. topographic maps in electronic format. The USGS maps remain an important source of information, especially for those areas graded for agriculture or urban development, where old channels, escarpments, debris fans, terraces and landslide features have been obscured by man.
U.S. Corps of Engineers harbor maps (1949)
In 1949 the Corps of Engineers began publishing information pamphlets titled “Small Boat Harbors and Shelters, Pacific Coast, Coast of California: Office of the Division Engineer, South Pacific Division, San Francisco. These map books contain nautical charts in a variety of scales, ranging between 1:30,000 and 1:600,000, with most close to 1:40,000. These maps present soundings and perennial wind information, but do not always include onshore topography. However, the areas of coverage are surprisingly extensive, including: Dume Cove, Malibu Point, Santa Monica Harbor, Redondo Beach Harbor, Malaga Cove, Portuguese Bend, Los Angeles Harbor, Long Beach Harbor, Alamitos Bay, Seal Beach, Anaheim Bay, Huntington Beach, Newport Bay harbor, Laguna Beach, Capistrano Anchorage (Dana Cove), Camp Pendleton Harbor, Del Mar, Mission Bay, San Diego Bay and all then offshore islands.
The Los Angeles District of the Corps of Engineers and the Port of Los Angeles –Long Beach maintain much more detailed maps of that ports’ evolution. Maps of subsidence in the Wilmington Oil Field area were widely distributed back in the 1960s (in particular, see: State of California, 1965, [Proceedings of] Landslides and Subsidence, Geologic Hazards Conference, May 26-27, Los Angeles, 91 p.).
First landslide hazard mapping in southern California (1949)
In 1949 John T. McGill of the USGS (see UCLA faculty threadline) began preparing the first landslide hazard map in southern California, of the Pacific Palisades area at a scale of 1:4,800 (J.T. McGill, 1959, Preliminary map of landslides in the Pacific Palisades area, City of Los Angeles, CA: USGS Map I-284). The high-visibility slides along PCH also gave rise to The Pacific Coast Highway (PCH) in the Pacific Palisades area, in particular, was the scene of repeated road closures throughout the 40s and 50s (Eldon S. Roth, 1959, Landslides between Santa Monica and Point Dume: master’s thesis, Geological Sciences, University of Southern California, 184 p.)
Adoption of Title 21 and the requirement for compaction testing on public worlks projects (1950)
In 1950 California Administrative Code Title 21 (Public Works: Department of Public Works, Architecture, Highways, Toll Bridge Authority) was enacted by the California Legislature. This required government agencies to require materials testing for public buildings, streets, and trench backfill of buried utilities in streets. These new requirements included compaction testing of soils, which hastened the inclusion of soils testing capabilities by various firms in the Los Angeles Area, such as the Smith-Emery Company (established LA office in 1910), Dames & Moore (established in 1938), and the Donald R. Warren Co. (established in 1940).
Initial Geohazards Awareness - “Buying a Home in Southern California” (1950)
This 85 page book appeared in 1950, written by consulting geologist Alfred Livingston, Jr., who had taught geology at Los Angeles City College and Los Angeles State College from 1931 thru the late 1950s. The book presented a great deal of useful introductory information, sketches, and photos describing the various geohazards common to southern California, and included a 9-page checklist for home buyers. Livingston’s cross section of a typical split level home constructed on a dip slope with uncompacted fill received considerable distribution following the disastrous storms of January 1952, which led the City of Los Angeles to develop the world’s first municipal excavation and grading code, in 1952.
GSA-ASCE Joint Committee on Engineering Geology (1950-86)
The GSA-ASCE Joint Committee on Engineering Geology was established in July 1950 by a memo from William R. Judd, CEG of the Engineering Geology Branch of the Chief Engineers’ office at the U.S. Bureau of Reclamation in Denver, addressed to the Engineering Geology Branch of GSA and the Soil Mechanics and Foundations Division of ASCE. The committee was formed “to deal with all of the problems pertinent to engineering geology, contributing to better understanding and communication between geologists and engineers.” From 1950-68 Judd served as the committee secretary, before joining the faculty at Purdue University in 1966.
Soil Mechanics Group of the Los Angeles Section of ASCE (1951)
In September 1951 a permanent Soil Mechanics Group was established within the LA Section of ASCE to replace the Committee on Soil Mechanics. This group was initially comprised of 85 members and was dedicated to the prospect of “broadening the opportunity for membership participation in discussions of soil mechanics problems in the Los Angeles area.” The group was initially chaired by Leopold Hirschfeldt (BSCE ’40 Stockholm Tech Inst) of Dames & Moore, who became a partner at Crandall from 1954-80. By 1957 the Los Angeles Section of ASCE had the largest dues-paying membership of any section in the United States.
Nation’s first excavation and grading code (1952)
In January 1952 two back-to-back storms of modest recurrence interval hit the Los Angeles area, causing considerable erosion and damage to hillsides. M.F. Burke compiled a report for the LA County Flood Control District titled Report on Floods of January 15-18, 1952. It summarizes the effects of the January 1952 storms, which caused $7.5 million in property damage in the City of Los Angeles, prompting an investigation of the causes by prominent engineers and geologists. Many of the problems associated with that storm sequence were actually found with uncontrolled fills placed during the post-war boom, without benefit of shear keys, subdrainage or mechanical compaction.
This study resulted in the City of Los Angeles adopting the Los Angeles Grading Ordinance, the first of its kind in the United States (see C.M. Scullin, 1966, History, Development, and Administration of Excavation and Grading Codes: in Lung and Proctor, eds., Engineering Geology in Southern California, Los Angeles Section AEG, p.227-236). By 1954 the basic need for engineering geologic input into hillside development was at least recognized, if not refined (see J.T. McGill, 1954, Residential building-site problems in Los Angeles, CA: California Division of Mines Bulletin 170, Ch. X, p. 11-18).