Abstract: A helical screw pile includes a longitudinal shaft having a top end and a bottom end with a plurality of helical plates arranged on the shaft in increasing diameter from the top to the bottom. The first helical plate is located toward the bottom of the shaft and has the largest diameter. The second helical plate is located above the first helical plate and has a diameter smaller than that of the first plate. The third helical plate is located above the second helical plate and has a diameter smaller than that of the second plate. The helical plate with the smallest diameter is located toward the top of the shaft. The distance between the first helical plate and the second helical plate is larger than the distance between the second helical plate and the third helical plate.

Abstract: A helical screw pile includes a longitudinal shaft having a top end and a bottom end with a plurality of helical plates arranged on the shaft in increasing diameter from the top to the bottom. The first helical plate is located toward the bottom of the shaft and has the largest diameter. The second helical plate is located above the first helical plate and has a diameter smaller than that of the first plate. The third helical plate is located above the second helical plate and has a diameter smaller than that of the second plate. The helical plate with the smallest diameter is located toward the top of the shaft. The distance between the first helical plate and the second helical plate is larger than the distance between the second helical plate and the third helical plate.

Abstract: The soil testing device of the present invention includes a tapered body member having opposite tapered surfaces which converge toward one another at their lower ends. Within one of the tapered surfaces is a cavity having a diaphragm placed thereover. Beneath the diaphragm are a plurality of sensors which extend in a line between the upper and lower ends of the cavity. Means are provided for introducing fluid pressure into the cavity. When the device is inserted into the soil, the sensors sense the various pressures being exerted on the diaphragm by the soil, and record these pressures on a gauge or meter located above the surface of the soil.

Abstract: A device for determining the shear strength of rock and soil is disclosed. The device includes means for supporting the device within a borehole, a primary shaft, a plurality of shearing units slidably attached to the shaft having shear heads which are movable from a retracted position to a material-engaging expanded position, and a slip joint between adjacent shearing units such that the units operate independently from one another. The shearing units apply progressively greater normal forces on the material to be tested and sequentially shear the material being tested.In operation, the device is lowered into a borehole. Then the shearing units are moved from their retracted position to their expanded material-engaging position so as to apply progressively greater normal forces on the material to be tested. An axial force is then applied to the shaft so that the material engaged by the shearing unit closest to the anchor shears.

Abstract: The present invention is a portable testing device for directly measuring developed lateral pressure and displacement induced on a material by a vertically applied load. The testing device comprises a thin walled cylindrical sleeve-like receptacle which is capable of lateral expansion in response to a vertically applied force on the material contained in the receptacle. A pressure sensing cylinder engages the expandable receptacle wall and has a stress gauge operatively connected thereto for sensing the pressure within the sensing cylinder. A strain gauge is also connected to the sensing piston for registering lateral displacement thereof. The improvement on this device comprises a control cylinder for regulating the pressure within the sensing cylinder. The control cylinder includes a control piston and threaded screw for adjustment of the control piston position within the control cylinder. The control cylinder is in fluid communication with the sensing cylinder and with the stress gauge.

Abstract: A method of insitu testing of soil compressibility comprises boring a hole in the soil to be tested, reconstituting the lateral stress environment in the soil adjacent the bottom of the borehole and then performing vertical compression tests directly on the undisturbed material at the bottom of the borehole. The testing apparatus of the invention includes a cylindrical container adapted to be pushed to the bottom of the borehole. An inflatable circumferential membrane around the exterior periphery of the container is inflated to reconstitute the lateral stress environment. The load may be applied to the base of the borehole by either a closed or inflatable fluid cell or directly by a flat or stepped load plate.In one embodiment of the invention, a thin-walled cylindrical tube penetrates the soil at the base of the borehole so as to laterally support the test soil for substantially one-dimensional vertical compression testing.

Abstract: A vane modulus soil tester includes a multi-blade vane having a plurality of radially extended and circumferentially spaced-apart blades. The blades have cavities in which resistance-type strain gauges are carried for measuring stress on the face of the vane blades. At least strain gauges are situated so as to be "facing" each other.A further embodiment may be provided with a series of independent levels of blades of different thicknesses whereby test values may be extrapolated to zero blade thickness conditions or the insitu value. A support base is provided for securely positioning a vane rod extended axially from the vane and for applying torque to the vane through the vane rod.

Abstract: A portable testing device for directly measuring developed lateral pressure induced on a material by a vertical applied pressure while the lateral expansion is adjustable. The testing device comprises a thin-walled cylindrical sleeve-like receptacle which is capable of lateral expansion in response to a vertical applied force on the material contained in the receptacle. The sleeve is provided with a slit formed in the wall thereof which extends between the upper and lower ends thereof to define first and second side edge portions. Apparatus is provided for preventing and/or adjusting lateral movement of the first side edge portion as the vertical applied force is applied to the material contained in the receptacle. A pressure sensing cylinder is connected to the second side edge portion and has a fluid pressure gauge operatively connected thereto for sensing the developed lateral stress.