Abstract: A hydraulic hammer for a working machine configured for digging a surface includes a housing, a chisel, sensors, and a controller. The housing is coupled to the working machine. The chisel is partially enclosed by the housing and extendable from the housing for digging the surface at a contact location. Each of the sensors is configured for generating a signal indicative of a projecting distance between one of the sensors and the surface. The controller is configured for receiving the signals, determining an angle between the chisel and a plane substantially tangent to the contact location, and reorienting the chisel so that the chisel is substantially orthogonal to the contact location with the angle at substantially ninety degrees.

Abstract: A hydraulic hammer for a working machine configured for digging a surface includes a housing, a chisel, sensors, and a controller. The housing is coupled to the working machine. The chisel is partially enclosed by the housing and extendable from the housing for digging the surface at a contact location. Each of the sensors is configured for generating a signal indicative of a projecting distance between one of the sensors and the surface. The controller is configured for receiving the signals, determining an angle between the chisel and a plane substantially tangent to the contact location, and reorienting the chisel so that the chisel is substantially orthogonal to the contact location with the angle at substantially ninety degrees.

Abstract: The invention relates to a method for monitoring the ramming of a ram post (1) into the ground. A succession of blows are struck on the ram post (1) via an impact driving device (3), causing the ram post (1) to be rammed into the ground. Parameters for the load-bearing capacity of the ram post (1) in the ground are ascertained during the ramming of the ram post (1) via a monitoring unit (14).

Abstract: A method and measuring device for determining the usage rate of a breaking hammer, and to a rock breaking device. The measuring device comprises a sensor for measuring a physical phenomenon caused by the operation of the percussion device. The measuring results are processed, and they are used to determine the start and end times of the operation of the percussion device. By means of a timing device, it is possible to determine the duration of an impact cycle which is added to a time counter. The durations of impact cycles added cumulatively to the time counter indicate the total percussion time of the breaking hammer. Impact pauses between impact cycles are also monitored, and pauses shorter than a predefined time limit are taken into account as part of the usage rate.

Abstract: A measurement device system and method of using the same for determining the depth of a pile being installed and/or the equipment used to install the pile. The device including an encoder assembly having a support attachable to a structural component of a rig wherein the support has a pivot joint coaxial with a load arm axis. The encoder assembly has a load arm rotatable about the arm axis and with a wheel near its distal end that is rotatable about a wheel axis with an encoder joined to the wheel that moves with the wheel. The encoder assembly further including a biasing assembly to urge the load arm and wheel into an engaged condition relative to the associated pile installation machine such that the wheel frictionally engages a surface of another structural component of the rig. Thus, the displacement of the first structural component relative to the second component rotates the wheel about the wheel axis and the encoder. This information can then be used to determine pile depth.

Abstract: A measurement device system and method of using the same for determining the depth of a pile being installed and/or the equipment used to install the pile. The device including an encoder assembly having a support attachable to a structural component of a rig wherein the support has a pivot joint coaxial with a load arm axis. The encoder assembly has a load arm rotatable about the arm axis and with a wheel near its distal end that is rotatable about a wheel axis with an encoder joined to the wheel that moves with the wheel. The encoder assembly further including a biasing assembly to urge the load arm and wheel into an engaged condition relative to the associated pile installation machine such that the wheel frictionally engages a surface of another structural component of the rig. Thus, the displacement of the first structural component relative to the second component rotates the wheel about the wheel axis and the encoder. This information can then be used to determine pile depth.

Abstract: To obtain data having high reliability required for determining bearing capacity of the pile in a short time and economically, a pseudostatic pile load testing method comprises processes that a drop height of a heavy weight (2) dropped on a pile head of a pile (1) is changed higher step by step, the heavy weight (2) is dropped from each of the heights, a time change of an acceleration of the pile head by that impact is determined by an accelerometer (4) installed at the pile head, and a displacement of the pile head is determined as an integrated value of the acceleration determined by the accelerometer (4).

Abstract: A pile driving control apparatus for a pile driving system includes a hydraulic control system that controls a throttle of a pile driving hammer, and thereby controls an impact velocity of the hammer with a pile. A controller provides a control signal to the hydraulic control system. Based on the control signal, the hydraulic control system controls an impact velocity of the hammer during a subsequent hammer stroke. The controller may determine one or more control parameters such as sound pressure at a sound control location during a hammer stroke, vibration at a vibration control location during a hammer stroke, an impact force imparted to the pile during a hammer stroke, and/or actual pile capacity of the pile, and provide to the hydraulic control system a control signal based on the determined control parameter(s).

Abstract: A pile driver comprises a hammer for impacting a pile, a velocity sensor for measuring the velocity at impact, and a control system for adjusting the hammer stroke in accordance with the readings from the velocity sensor so that the optimal impact energy is imparted to the head of the pile. Optionally, the system further comprises a pile driving analyzer (including at least one strain gauge and/or an accelerometer) mounted on the side of the pile itself to determine whether the impact loading on the pile is below the maximum allowable stress. If the pile driving analyzer senses an overload of stress on the pile, the control system will reduce the velocity of the subsequent hammer stroke so that it no longer exceeds the maximum allowable stress.

Abstract: A damping performance evaluation apparatus for damping devices including: a support member detachably supporting a damping device in a state enabling the device to exhibit a damping effect thereof; a hammer member for applying oscillation force to the device caused by gravitational descent to strike the device; a double-strike preventing member for preventing the hammer member from dropping a second time due to rebound after initially striking the device, to prevent double-strike of the device by the hammer member; a vibration sensor installed at a vibration zone caused to vibrate through oscillation force applied by said hammer member, for outputting an electrical signal in response to vibration at the vibration zone; and a sensing member for sensing a vibration mode in the vibration zone on the basis of an output of said vibration sensor. A damping performance evaluation method is also disclosed.

Abstract: A sensing element, disposed in a housing, has a gas contact portion exposed to a measured gas. A protective cover extends from a distal end of the housing so as to surround the gas contact portion of the sensing element. A first metallic cover surrounds signal output terminals and leads connected to the sensing element. In manufacturing the first metallic cover, a shot blasting is applied to a surface of a semi-finished product of the first metallic cover.

Abstract: A system for the determination of pile parameters includes at least one structure for measuring pile data. The structure for measuring pile data is disposed within a measurement range from a pile. A wireless transmitter is communicably connected to the structure for measuring pile data, the wireless transmitter for transmitting the pile data to at least one remotely located receiver. Pile data is preferably encoded in the transmitted data signal. The remotely located receiver is communicably connected to a device for determining at least one pile parameter from the pile measurement data. A method for driving piles includes the steps of wirelessly transmitting pile data to at least one remote receiver, determining at least one pile driving process parameter from the pile data, and driving the pile using the determined pile driving parameter.

Abstract: Methods for augmenting the load bearing characteristics of short aggregate piers include preloading matrix soils, adding chemical additives to matrix soils and using mesh reinforcement in matrix soils and in cooperation with the aggregate lifts associated with pier constructions. Methods for expanding the feasibility of short aggregate piers include the use of gradations of aggregate, reducing friction between the short aggregate pier and adjacent matrix soils using liners or lubricating materials, controlling liquefaction by employing aggregate drains in short aggregate pier constructions, the use of non-impact forces alone or in conjunction with vibratory forces in construction short aggregate pier lifts, and the use of indigenous materials in short aggregate pier constructions.

Abstract: The invention relates to an arrangement for indicating a need for maintaining a hydraulic breaking apparatus, the arrangement comprising means for measuring at least one parameter describing the loading of the apparatus. The invention also comprises an indicator which is specific for each breaking apparatus and which is arranged to indicate visually, for example by means of LED lamps, that the parameter measured has exceeded the limit value determined in advance for maintenance.