Abstract: A drilling and grouting device comprises a drill string including a hollow elongate outer rod having a central axis and a hollow elongate inner rod located coaxially within said outer rod, wherein a first outer flow path is defined between said inner and outer rod, and a first central flow path is defined inside said inner rod, a drill bit aligned with said inner rod along said central axis and including a second central flow path, and a crossover part interposed between said inner rod and said drill bit along said central axis, which is configured to connect the first central flow path with a second outer flow path surrounding the drill bit to form a main path and to connect said first outer flow path with said second central flow path to form a secondary path. Also disclosed are systems and methods that include and use the device.

Abstract: A drilling and grouting device comprises a drill string including a hollow elongate outer rod having a central axis and a hollow elongate inner rod located coaxially within said outer rod, wherein a first outer flow path is defined between said inner and outer rod, and a first central flow path is defined inside said inner rod, a drill bit aligned with said inner rod along said central axis and including a second central flow path, and a crossover part interposed between said inner rod and said drill bit along said central axis, which is configured to connect the first central flow path with a second outer flow path surrounding the drill bit to form a main path and to connect said first outer flow path with said second central flow path to form a secondary path. Also disclosed are systems and methods that include and use the device.

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 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 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.