Delong Pier Tests at Fort Eustis, Virginia
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TA .7 .W34 n o.3- 4 5 0 DELONG PIER TESTS AT FORT EUSTIS, VIRGINIA TECHNICAL REPORT NO. 3.450 February 1957 U. S. Army Engineer Waterways Experiment Station CORPS OF ENGINEERS Vicksburg, Mississippi ARMY.MNC VICKSBUR. MIS. iii PREFACE The Waterways Experiment Station was requested by the Philadelphia District, CE, on 28 January 1955, to make soils foundation investigations and analyses of two sites on the James River at Fort Eustis, Virginia, where an Engineer Test Unit from the Engineer Center, CE, U. S. Army, planned to install a DeLong pier tramway system for use by the Transporta- tion Research and Development Command, Transportation Corps, U. S. Army, for conducting offshore cargo-discharge exercises. The Office, Chief of Engineers, had previously assigned primary responsibility for coordinating all phases of the tests to the Philadelphia District. Basic responsibility for installation of the tramway system, operational tests, and for the foundation tests and analyses were assigned, respectively, to the Engineer Center, Fort Belvoir, Virginia, the Trans- portation Research and Development Command (TRADCOM), Fort Eustis, Virginia, and the Waterways Experiment Station (WES), Vicksburg, Mississippi. The soils investigations were conducted in February, March, and April 1955 by personnel of WES assisted by military personnel of TRADCOM. TRADCOM furnished the floating plant required for the offshore work and personnel to assist WES personnel in the field exploration. Personnel of the Soils Division, Waterways Experiment Station, connected with the investigation were Messrs. W. J. Turnbull, W. G. Shockley, C. I. Mansur, T. B. Goode, and A. L. Mathews. This report was prepared by Mr. Mathews. CONTENTS Page PREFACE . ............................ iii SUMMARY . ............................ vii PART I: INTRODUCTION ...................... Purpose and Scope . ...... ............... Pier and Tramway Details ... .. 2 PART II: CAMP WALLACE SITE .................... 4 Foundation Explorations . .. ..... " 4 Laboratory Tests ... ........ Required Spud Penetrations and Bearing Capacity . Analysis of Foundation Conditions . .. .. ... 10 Conclusions ............ .................. 17 PART III: RED BEACH SITE .. .............. .... 19 Foundation Explorations ......... ........ 19 Laboratory Tests ....... ... 21 Required Spud Penetrations and Bearing Capacity ...... 21 Analysis of Foundation Conditions ..... ....... .. 26 Summary of Findings and Conclusions .... ...... 36 vi List of Tables Table Title Page Camp Wallace Site 1 Summary of Soil Test Data 2 Comparison of Spud Penetrations and Dynamic Cone Penetration Resistance 13 3 Computed Spud Bearing 16 Red Beach Site 4 Summary of Soil Test Data 23-24 5 Comparison of Spud Penetrations and Dynamic Cone Penetration Resistance 29 6 Computed Spud Bearing 32 7 Computed Bearing for Land Towers 35 List of Figures F1igure Camp Wallace Site Plan and soil profile 5 Dynamic cone soundings 7 Comparison of spud bearing and dynamic cone penetration 12 Red Beach Site 4 Plan and soil profile 20 5 Dynamic cone soundings 22 6 Comparison of spud bearing and dynamic cone penetration 28 vii SUMMARY Soils investigations were made in February, March, and April 1955 at two sites, Camp Wallace and Red Beach, on the left bank of the James River near Fort Eustis, Virginia. These sites had been selected for the installation of a DeLong pier tramway system to be operated by the Trans- portation Research and Development Command during offshore cargo-discharge exercises. The investigations were made to determine the suitability of the sites for the installation of a pier and tramway system. Borings and dynamic cone penetration tests were made at both sites. Laboratory tests were made on representative samples of the various soil strata encountered. The tests performed on the foundation soils showed that sufficient spud bearing could be obtained to raise the DeLong pier barges to the required elevations by using 150-ft spuds on the barges at Camp Wallace and 100-ft spuds on the pier barges and 50-ft spuds on the platform barges at the Red Beach site. An analysis was made of the foundation requirements for the land towers and the land anchor installed during the tests at the Red Beach site. DELONG PIER FOUNDATION TESTS, FORT EUSTIS, VA. PART I: INTRODUCTION Purpose and Scope 1. The Armed Forces testing program for DeLong piers included the installation and operational testing of a DeLong pier tramway system at two sites, designated Camp Wallace and Red Beach, selected by TRADCOM on the left bank of the James River at Fort Eustis, Va. The purpose of the testing program was to train personnel in the installation and operation of these tramway systems. 2. Before the system was installed soils tests and analysis were made to determine the suitability of the foundation soils at the sites for the installation and operation of the pier and tramway system, and to estimate the depth of spud penetration and length of spuds required to raise and support the pier and platform barges. 3. Dynamic cone penetration tests were made to obtain data for estimating spud penetrations by correlation with similar data obtained during DeLong pier foundation tests conducted at Norfolk, Va.* Some bor- ings were made to obtain undisturbed soil samples from which shear strengths could be determined for use in computing spud load capacity for the depths of penetration obtained, for estimating spud penetrations for a known driving force, and for analyzing foundation requirements for the land towers and land anchor. 4. This report presents only the foundation phase of the tests at the Camp Wallace and Red Beach test sites. A report on the installation of the tramway system has been prepared by the Engineer Center** and a report on its operation is to be prepared by TRADCOM. * Corps of Engineers, Waterways Experiment Station, DeLon Pier Founda- tion Tests. Miscellaneous Paper 3-78, Vicksburg, Miss. (February 1954). ** Corps of Engineers, Engineer Center, Engineer Test Unit, Tramway Aerial, Ship-to-shore, Project No. 8-71-10-001. Fort Belvoir, Va. (30 July 1955). 2 Pier and Tramway Details 5. The pier and tramway system used in the testing program con- sisted of two self-elevating pier barges, 300 by 90 by 13 ft, designated as F and G barges; two platform barges, 45 by 56 by 6 ft, designated as H and I barges; four monotube land towers, a land anchor, tramway cables, sky cars for transporting cargo, and auxiliary equipment and supplies necessary for the erection and operation of the system. The F and G barges are each equipped with 22 spuds; the H and I barges are each equipped with 4 spuds. The spuds are raised and lowered through wells located inside the outer perimeter of the barges, and are 6 ft in diameter and hollow. They are constructed of 3/4-in. steel plate in 50-ft sections with a quick-coupling arrangement to permit the lengths of the spuds to be varied in multiples of 50 ft. The bottom section of each spud has a reinforcing ring 1/2 in. thick and 9 in. high welded to the inside at the bottom, and a solid diaphragm welded inside 15 ft above the bottom. Two 2-in.-diameter vent holes are located in the spud wall diametrically opposite each other just below the diaphragm. These holes prevent air and water from being trapped in the spuds below the diaphragm during driv- ing and also facilitate the pulling of the spuds. In addition, two plugs are located 1 ft and 7 ft above the diaphragm. These plugs can be re- moved externally after the spuds are raised sufficiently to allow access to them; they are used to drain the water from above the diaphragm dur- ing pulling operations before final removal of the spuds in the event the installation is dismantled. Each spud is operated by means of an air jack of 250-ton capacity at an air pressure of 150 psi. 6. The tramway cables over which the sky cars operate are sup- ported on a series of two-leg monotube towers extending from a terminal tower on the offshore end of the F barge to the land anchor on shore in the unloading and intratransit area. One tower is located on the inshore end of the G barge and one on each of the platform barges. Other land- based towers as required are installed in the system to extend it to the land anchor. The machinery for operation of the tramway cables is housed in the base of the terminal tower on the F barge. Details of the system 3 are shown in General Information Book for 300-ft Barge Tramway Pier, prepared by G. E. Sudrow, Inc., 29 Broadway, New York 6, N. Y., and other related drawings prepared for the Transportation Corps by various commercial agencies. 4 PART II: CAMP WALlACE SITE 7. The first site at which tests were conducted was Camp Wallace, an outlying test camp for Fort Eustis, located about 5 miles upstream from Fort Eustis on the left bank of the James River. The limited plan of tests at this site required installation of the F barge and two plat- form barges only. The land anchor and land towers of an aerial tramway system previously tested at the site were utilized as part of the new system. Foundation Explorations 8. A program for foundation exploration and testing was developed after available foundation data were reviewed. Eight dynamic cone sound- ings and four undisturbed sample borings were made with a drill rig mounted on a barge at the sites to be occupied by the F, H, and I barges. All samples were visually classified in the field. A plan of the loca- tions of the F, H, and I barges, borings and cone soundings, and a soil profile of the foundation under the barges are shown on fig. 1. Foundation soils 9. The river bottom at the F and H barge locations is composed of about 105 ft of soft gray clay down to approximately el -116 to -122 ft mlw, and at the I barge location it consists of about 81 ft (to el -97) of similar material.