Panel load, static sounding, spinning sounding and dynamic sounding test all-in-one machine

Abstract

The invention discloses a flat plate load, static sounding, spinning sounding and dynamic sounding test all-in-one machine. Comprising a loading platform (1), a crawler walking device (2), an engine system (3), a walking control system (4), static sounding probe rod penetration counter-force equipment (11), rotary press-in sounding probe rod penetration counter-force equipment (12), dynamic sounding probe rod penetration counter-force equipment (14), a flat plate load test module (18), a loading vehicle leveling and ground anchor control system (8), a hydraulic system (9), a hydraulic ground anchor fixing system (7) and a supporting foot balancing system (5). Through the highly integrated and modular design, the four functions of plate loading, static sounding, spinning sounding and dynamic sounding are integrated, and the key problems that traditional foundation testing equipment is dispersed, low in efficiency and poor in data comparability are solved.

Description

Technical Field

[0001] This invention belongs to the field of exploration equipment technology, and specifically relates to an integrated machine for plate load, static cone penetration, spin cone penetration and dynamic cone penetration tests. Background Technology

[0002] In the investigation, design, and quality control of foundation, subgrade, and pavement engineering, accurately obtaining the physical and mechanical parameters of the soil and rock mass is crucial. Traditional foundation testing methods, such as plate load tests, static cone penetration tests, dynamic cone penetration tests, and vane shear tests which are theoretically related to spinning penetration tests, are all important means of determining key indicators such as foundation bearing capacity, deformation modulus, and undrained shear strength in the field. Traditional field testing techniques are typically performed by single-function, independent equipment. Plate load tests, which apply vertical pressure to the foundation surface at progressively higher levels and measure settlement over time, determine the bearing capacity and deformation parameters. This is the earliest and most widely used in-situ testing method. Static cone penetration tests use static force to uniformly press a standard-sized probe into the soil, determining the soil's physical and mechanical properties based on the penetration resistance of the probe. Dynamic cone penetration tests use a heavy hammer of a certain mass to drive a standard-sized penetrator or conical probe into the soil from a certain free-fall distance, determining the soil's mechanical properties based on the number of blows required to penetrate a certain distance. Vane shear tests insert a standard vane probe into the soil and twist it at a certain rate, measuring the soil's resistance moment at failure to determine the undrained shear strength and estimate the foundation bearing capacity.

[0003] However, these traditional methods suffer from problems such as dispersed and inefficient equipment, limited data comparability due to differences in measurement points, and difficulty in ensuring the standardization of the testing process and the consistency of data. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by proposing an integrated machine for plate load testing, static cone penetration testing, spinning cone penetration testing, and dynamic cone penetration testing. Through highly integrated and modular design, this invention combines four functional devices—plate load testing, static cone penetration testing, spinning cone penetration testing, and dynamic cone penetration testing—into one unit, solving the key problems of traditional ground-based testing equipment being scattered, inefficient, and lacking data comparability.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: An integrated machine for plate load, static cone penetration, spin cone penetration, and dynamic cone penetration testing includes a loading platform, a tracked walking device installed below the loading platform, and an engine system installed above the loading platform; the engine system also has a walking control system mounted on its surface; it further includes a static cone penetration test rod penetration reaction device, a spin cone penetration test rod penetration reaction device, a dynamic cone penetration test rod penetration reaction device, and a plate load testing module; the dynamic cone penetration test rod penetration reaction device, the spin cone penetration test rod penetration reaction device, and the static cone penetration test rod penetration reaction device are installed sequentially from left to right on the loading platform; the plate load testing module is installed at the bottom of the loading platform, directly below the static cone penetration test rod penetration reaction device; the loading platform also has a loading vehicle leveling and ground anchor control system, a hydraulic system, and two hydraulic ground anchor fixing systems, which are symmetrically arranged on both sides of the loading platform; the loading platform also has at least four support leg balancing systems, which are evenly arranged in a rectangle around the four edges of the loading platform.

[0006] In this invention, the hydraulic ground anchor fixing system provides the necessary penetration reaction force for the entire device during plate load, static cone penetration, and rotary cone penetration tests. The plate load test module is used to conduct plate load tests by applying vertical loads to evaluate the bearing capacity of the foundation, subgrade, and pavement, and to analyze the strength and stability of each structural layer through load-settlement relationship curves. The rotary cone penetration test probe penetrates deep into the soil to obtain soil density and other physical properties. The static cone penetration test probe measures the static response of the soil to evaluate the soil strength and engineering properties. The dynamic cone penetration test probe employs dynamic cone penetration technology, suitable for different soil types and mechanical properties. The loading vehicle leveling and ground anchor control system is used for overall device leveling and ground anchor fixing system control. The hydraulic system provides stable power output to each functional module, achieving coordinated control of high-pressure penetration, precise loading, and rapid anchoring, greatly improving operational response speed and execution consistency.

[0007] The static cone penetration test rod penetration reaction device, the rotary cone penetration test rod penetration reaction device, the dynamic cone penetration test rod penetration reaction device, and the plate load test module of the present invention are all fixedly installed on the loading platform by corresponding mounting brackets (mounting seats).

[0008] The multi-point uniform layout of the outrigger balancing system of this invention significantly improves the stability and leveling efficiency of the equipment in complex terrain, ensuring that various tests are conducted under strict level conditions and reducing measurement errors caused by equipment tilting. The hydraulic ground anchor fixing system of this invention works in conjunction with the loading vehicle leveling control system to achieve rapid automatic leveling and high-strength anchoring during the test process. This effectively avoids the lifting or displacement of the equipment when the load is applied, ensuring the accuracy and repeatability of pressure-settlement data in the plate load test. It is suitable for unstable foundations such as soft soil and backfill soil, and can significantly improve the reliability of test data and engineering applicability.

[0009] As a further explanation of the present invention, the static cone penetration test rod is installed in front of the engine system; the static cone penetration test rod includes a static cone rod body, and the lower end of the static cone rod body penetrates through the loading platform.

[0010] The static cone penetration test probe reaction device of this invention adopts constant speed injection technology, combined with the stable reaction force provided by the loading platform, which can accurately measure the cone tip resistance, side wall friction and pore water pressure, effectively assess the soil layer distribution, strength and compressibility. Its integrated design avoids the errors caused by the disassembly and assembly of traditional equipment, and realizes the synchronous acquisition of data with other test methods at the same measuring points and under the same conditions, which significantly improves the consistency and reliability of soil layer parameter comparison.

[0011] As a further illustration of the present invention, the rotary pressing probe penetration reaction device includes a rotary pressing probe, and the rotary pressing probe penetrates the loading platform.

[0012] The rotating cone penetration test probe of this invention simulates the principle of vane shear test. By controlling the rotation rate and torque measurement, the undrained shear strength and sensitivity parameters of the soil can be accurately obtained. This module is integrated with static and dynamic cone penetration tests, enabling continuous and rapid testing of multiple mechanical properties of soil at the same location. It avoids data dispersion problems caused by changing equipment or measuring points, and is particularly suitable for evaluating the engineering properties of cohesive and soft soils.

[0013] As a further explanation of the present invention, the power penetration test rod penetration reaction device is located at the front end of the loading platform, and includes a power penetration test rod, a power penetration test hammer automatic unhooking and hammer lifting controller, a power penetration test hammer drop distance control device, and a power penetration test rod verticality maintaining device fixed on the loading platform; the top end of the power penetration test rod is connected to the power penetration test hammer drop distance control device, and the lower end passes through the power penetration test rod verticality maintaining device.

[0014] The power penetration test rod and reaction force device are fixedly installed at the front end of the loading platform via a gantry bracket.

[0015] The dynamic penetration test rod reaction device of this invention ensures the standardization and consistency of hammering energy and penetration depth through automatic unhooking, precise drop distance control and probe vertical holding device. It can quickly assess the compaction and bearing capacity of coarse-grained soils such as gravelly soil and sandy soil. The automated control reduces human operation error and improves testing efficiency and safety. At the same time, the integrated structure ensures data complementarity and verification with static and spinning tests, enhancing the comprehensiveness and accuracy of complex strata evaluation.

[0016] As a further explanation of the present invention, the plate load test module includes a load plate loading hydraulic cylinder.

[0017] As a further explanation of the present invention, the loading platform is also provided with a counterweight.

[0018] Advantages of this invention: 1. This invention integrates four major functions—plate load testing, static cone penetration testing, spinning cone penetration testing, and dynamic cone penetration testing—through a highly integrated and modular design, solving the key problems of traditional ground testing equipment such as dispersion, low efficiency, and poor data comparability. At the same time, each functional module shares the same loading platform, power system, and control unit, ensuring the consistency of testing conditions and the standardization of operating procedures. The hydraulic ground anchor and outrigger balancing system ensures rapid leveling and stable anchoring of the equipment in complex sites, significantly improving testing accuracy and repeatability.

[0019] 2. This invention achieves four major innovations: structural integration, power sharing, centralized control, and enhanced stability. The modular layout reduces equipment size and site requirements, resulting in a significant improvement in space efficiency. Automated control eliminates differences in human operation, achieving standardized operation. The unified platform ensures consistent testing conditions, achieving high data consistency. The ground anchor-leg collaborative mechanism ensures the accuracy of soft soil testing, achieving adaptability to complex environments. These innovations solve the pain points of traditional decentralized equipment.

[0020] 3. This invention, through integrated setup, enables the completion of multiple tests at the same measuring point and within the same time series, greatly improving on-site testing efficiency and reducing the time costs of equipment transportation and repeated setup. In addition, the mutual supplementation and verification of data from multiple methods enhances the scientific rigor and comprehensiveness of geological evaluation, providing efficient, reliable, and comprehensive technical means for the quality control of geotechnical engineering investigation, design, and construction. Attached Figure Description

[0021] Figure 1 This is a three-dimensional structural schematic diagram of an embodiment of the present invention; Figure 2 This is a front view structural diagram of an embodiment of the present invention; Figure 3 This is a schematic diagram of the rear view structure according to an embodiment of the present invention; Figure 4This is a schematic diagram of the left-side structure according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the right-side structure according to an embodiment of the present invention; Figure 6 This is a top view of an embodiment of the present invention; Figure 7 This is a bottom view structural diagram of an embodiment of the present invention.

[0022] In the diagram: 1-Loading platform; 2-Crawler walking device; 3-Engine system; 4-Walking control system; 5-Outrigger balancing system; 6-Counterweight; 7-Hydraulic ground anchor fixing system; 8-Loading vehicle leveling and ground anchor control system; 9-Hydraulic system; 10-Static cone penetrating probe body; 11-Static cone penetrating probe penetration reaction device; 12-Rotary pressing cone penetrating probe penetration reaction device; 13-Rotary pressing probe; 14-Dynamic cone penetrating probe penetration reaction device; 15-Dynamic cone penetrating probe drop hammer automatic unhooking and drop hammer lifting controller; 16-Dynamic cone penetrating probe drop distance control device; 17-Dynamic cone penetrating probe verticality maintaining device; 18-Plate load test module. Detailed Implementation

[0023] The technical solutions of the present invention will be clearly and completely described and explained below with reference to the accompanying drawings in the embodiments of the present invention.

[0024] Example: See Figures 1-7 The integrated machine for plate load, static cone penetration, spin-pressing cone penetration, and dynamic cone penetration testing includes a loading platform 1, a tracked walking device 2 installed below the loading platform 1, and an engine system 3 installed above the loading platform 1; the surface of the engine system 3 is also equipped with a walking control system 4; it also includes a static cone penetration test rod penetration reaction device 11, a spin-pressing cone penetration test rod penetration reaction device 12, a dynamic cone penetration test rod penetration reaction device 14, and a plate load test module 18; the dynamic cone penetration test rod penetration reaction device 14 and the spin-pressing cone penetration test rod penetration reaction device 12... The static cone penetration test rod and the static cone penetration test rod reaction device 11 are installed sequentially from left to right on the loading platform 1; the plate load test module 18 is installed at the bottom of the loading platform 1 and is located directly below the static cone penetration test rod and the static cone penetration test rod reaction device 11; the loading platform 1 is also equipped with a loading vehicle leveling and ground anchor control system 8, a hydraulic system 9 and two hydraulic ground anchor fixing systems 7, and the two hydraulic ground anchor fixing systems 7 are symmetrically arranged on both sides of the loading platform 1; the loading platform 1 is also equipped with at least four support leg balancing systems 5, which are evenly arranged in a rectangle on the four sides of the loading platform 1.

[0025] Furthermore, the static cone penetration test rod insertion reaction device 11 is installed in front of the engine system 3; the static cone penetration test rod insertion reaction device 11 includes a static cone penetration test rod body 10, and the lower end of the static cone penetration test rod body 10 penetrates the loading platform 1.

[0026] Furthermore, the rotary pressing probe rod penetration reaction device 12 includes a rotary pressing probe rod 13, and the rotary pressing probe rod 13 penetrates the loading platform 1.

[0027] Furthermore, the power penetration test rod insertion reaction device 14 is located at the front end of the loading platform 1, and includes a power penetration test rod, a power penetration test hammer automatic unhooking and hammer lifting controller 15, a power penetration test hammer drop distance control device 16, and a power penetration test rod verticality maintaining device 17 fixed on the loading platform 1; the top end of the power penetration test rod is connected to the power penetration test hammer drop distance control device 16, and the lower end passes through the power penetration test rod verticality maintaining device 17.

[0028] Furthermore, the plate load test module 18 includes a load plate loading hydraulic cylinder.

[0029] Furthermore, the loading platform 1 is also equipped with a counterweight 6.

[0030] In this embodiment, the loading platform 1 is welded from high-strength steel plates, with dimensions of 6m long × 3m wide × 0.2m thick. Its surface is equipped with a standardized bolt hole array for modular equipment installation. The tracked walking device 2 has a track width of 500mm and a ground pressure of less than 50kPa, suitable for soft soil and rugged terrain. The engine system 3 is a diesel engine with a rated power of 100kW, providing power to the entire system via a hydraulic pump group. The walking control system 4 integrates GPS and inertial navigation units to achieve autonomous path planning and movement control. This embodiment, through highly integrated and modular design, combines four major functions—plate load testing, static cone penetration testing, spin cone penetration testing, and dynamic cone penetration testing—into one, solving the key problems of traditional ground-based testing equipment being scattered, inefficient, and having poor data comparability. Simultaneously, all functional modules share the same loading platform, power system, and control unit, ensuring consistency of testing conditions and standardization of operating procedures. The hydraulic ground anchor and outrigger balancing system 5 ensures rapid leveling and stable anchoring of the equipment in complex sites, significantly improving testing accuracy and repeatability.

[0031] In this embodiment, the plate load test module 18 is used to conduct plate load tests by applying vertical loads to evaluate the bearing capacity of the foundation, subgrade, and pavement. The strength and stability of each structural layer are analyzed through load-settlement relationship curves. The hydraulic cylinder for loading the load plate has a cylinder diameter of 200mm, a stroke of 500mm, and a maximum loading capacity of 500kN. The load plate is circular with a diameter of 600mm and is made of hardened steel. During installation, it is bolted to the loading platform 1 via a flange and equipped with displacement and pressure sensors to monitor settlement and load data in real time. The plate load test module 18 provides a stable and adjustable vertical load, which, together with the hydraulic ground anchor system 7, enables precise loading and settlement observation of the plate load test. This achieves efficient execution of large-area load plate testing, and is particularly suitable for determining the bearing capacity and deformation modulus of shallow foundation, subgrade, and pavement structural layers. It fills the limitation of traditional penetration testing, which cannot directly simulate large-area load effects, and forms a comprehensive testing capability combining point (penetration) and surface (load) testing.

[0032] In this embodiment, the rotating penetration test probe 12 penetrates deep into the soil through a rotating probe head to obtain the soil density and other physical properties. The rotating penetration probe 13 of the rotating penetration test probe 12 is made of stainless steel, with a diameter of 50mm and an extendable length, with a maximum penetration depth of 30m. The rotating drive unit uses a hydraulic motor with an adjustable speed range of 0.1 to 2 rpm and a torque measurement range of 0 to 500 N·m. The probe head is a vane type, with dimensions of 50mm × 100mm. During installation, the probe head is clamped to the drive unit via a chuck and equipped with a depth encoder to record the penetration depth. The rotating penetration test module simulates the vane shear test principle. By controlling the rotation rate and torque measurement, the undrained shear strength and sensitivity parameters of the soil can be accurately obtained. This module is integrated with static and dynamic penetration tests, enabling continuous and rapid testing of multiple mechanical properties of soil at the same location. It avoids data dispersion problems caused by changing equipment or measuring points, and is particularly suitable for evaluating the engineering properties of cohesive and soft soils.

[0033] In this embodiment, the static cone penetration test rod insertion reaction device 11 is used to measure the static response of the soil and evaluate the soil strength and engineering properties. The static cone penetration test rod body 10 of the static cone penetration test rod insertion reaction device 11 is made of high-strength alloy steel, with a diameter of 40mm and a standard length of 1m, and is connected by threads to form a multi-section rod system. The static cone penetration test rod insertion reaction device 11 also includes a hydraulic penetration mechanism, with the penetration speed controlled at 20mm / s±5%, and is equipped with a cone tip resistance sensor and a pore water pressure sensor. During installation, the rod body is sealed to the loading platform 1 through a guide sleeve to prevent soil intrusion. The static cone penetration module adopts constant speed injection technology, combined with the stable reaction force provided by the loading platform 1, which can accurately measure the cone tip resistance, side wall friction resistance and pore water pressure, effectively evaluate the soil layer distribution, strength and compressibility. Its integrated design avoids the errors caused by the disassembly and assembly of traditional equipment, and realizes the synchronous acquisition of data with other test methods at the same measuring points and under the same conditions, which significantly improves the consistency and reliability of soil layer parameter comparison.

[0034] In this embodiment, the dynamic cone penetration test (VCT) rod insertion reaction device 14 employs dynamic cone penetration technology, suitable for the mechanical properties of different soil types. Furthermore, the automatic release mechanism of the falling hammer in the VCT rod insertion reaction device 14 uses an electromagnetic release mechanism, with a hammer weight of 63.5 kg (standard heavy-duty VCT) and a drop distance of 760 mm ± 10 mm. The VCT falling hammer drop distance control device 16 is driven by a hydraulic winch with a lifting speed of 0.5 m / s. The VCT rod verticality maintenance device 17 includes a laser centering device and an adjustable guide frame, ensuring that the rod's verticality deviation is less than 1°. The rod is... The device has a circular cross-section, a diameter of 42mm, and is made of high-strength carbon steel. During installation, the drop hammer system is fixed to the loading platform 1 by bolts via guide rails. The dynamic penetration module ensures the standardization and consistency of hammer energy and penetration depth through automatic unhooking, precise drop distance control, and a vertical rod holding device. It can quickly assess the compaction and bearing capacity of coarse-grained soils such as gravelly soil and sandy soil. Automated control reduces human error and improves testing efficiency and safety. At the same time, the integrated structure ensures data complementarity and verification with static and spinning tests, enhancing the comprehensiveness and accuracy of complex strata evaluation.

[0035] In this embodiment, the outrigger balancing system 5 includes four hydraulic outriggers, each with a maximum supporting force of 200kN. The bottom of each outrigger is equipped with replaceable foot pads (rubber pads for hard ground and steel nail pads for soft soil). The outriggers are leveled via hydraulic cylinder extension and retraction, with a leveling accuracy of ±0.5°, controlled by tilt sensors. The hydraulic system 9 includes a hydraulic tank, pump station, valve group, and pipelines, operating at a pressure of 21MPa. Quick couplings facilitate maintenance. During installation, the outriggers are welded to the loading platform 1 via hinged joints. The multi-point uniform layout of the outrigger balancing system 5 significantly improves the stability and leveling efficiency of the equipment in complex terrain, ensuring that all tests are conducted under strict level conditions and reducing measurement errors caused by equipment tilt. The hydraulic system 9 provides stable power output to each functional module, achieving coordinated control of high-pressure penetration, precise loading, and rapid anchoring, greatly improving operational response speed and execution consistency.

[0036] In this embodiment, the loading vehicle leveling and ground anchor control system 8 integrates a PLC controller and a touch screen interface to achieve automatic leveling and ground anchor pressure monitoring. The counterweight 6 is made of cast iron, weighs 2 tons, and is fixed to the rear of the loading platform 1 with bolts to balance the front load. The hydraulic ground anchor fixing system 7 has an anchor rod diameter of 30mm, a length of 1.5m, a hydraulic cylinder stroke of 300mm, and a maximum anchoring force of 100kN. During installation, the loading vehicle leveling and ground anchor control system 8 is connected to the hydraulic system 9 via a quick-connect coupling. The hydraulic ground anchor fixing system 7 and the loading vehicle leveling and ground anchor control system 8 work together to achieve rapid automatic leveling and high-strength anchoring during the test, effectively preventing the equipment from lifting or shifting when the load is applied, and ensuring the accuracy and repeatability of pressure-settlement data in the plate load test. This system is particularly suitable for unstable foundations such as soft soil and backfill soil, and can significantly improve the reliability of test data and engineering applicability.

[0037] It should be noted that all modules and components of this invention can be purchased on the market and can be procured and assembled according to the preferred parameters of the above embodiments or the actual conditions of the construction site. Through integrated design, this invention enables multiple tests to be completed at the same measuring point and in the same time series, which greatly improves the efficiency of on-site testing and reduces the time cost of equipment transportation and repeated setup. In addition, the data from multiple methods complement and verify each other, enhancing the scientificity and comprehensiveness of stratigraphic evaluation and providing efficient, reliable and comprehensive technical means for geotechnical engineering investigation, design and construction quality control.

[0038] Obviously, the above embodiments are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will recognize that other variations or modifications can be made based on the above description; it is neither necessary nor possible to exhaustively list all possible implementations; however, obvious variations or modifications derived therefrom are still within the scope of protection of the present invention.

Claims

1. An integrated machine for plate load, static cone penetration, spinning cone penetration and dynamic cone penetration testing, comprising a loading platform (1), a tracked walking device (2) installed below the loading platform (1), and an engine system (3) installed above the loading platform (1); a walking control system (4) is also installed on the surface of the engine system (3); characterized in that: It also includes a static cone penetration test rod penetration reaction device (11), a rotary cone penetration test rod penetration reaction device (12), a dynamic cone penetration test rod penetration reaction device (14), and a plate load test module (18). The dynamic penetrometer rod penetration reaction device (14), the rotary pressing penetrometer rod penetration reaction device (12), and the static penetrometer rod penetration reaction device (11) are installed on the loading platform (1) from left to right; The plate load test module (18) is installed at the bottom of the loading platform (1) and is located directly below the static cone penetration test rod reaction device (11); The loading platform (1) is also equipped with a loading vehicle leveling and ground anchor control system (8), a hydraulic system (9) and two hydraulic ground anchor fixing systems (7), and the two hydraulic ground anchor fixing systems (7) are symmetrically arranged on both sides of the loading platform (1); The loading platform (1) is also provided with at least four support balancing systems (5), which are evenly arranged in a rectangular shape around the edges of the loading platform (1).

2. The integrated machine for plate load, static cone penetration, spinning cone penetration, and dynamic cone penetration testing according to claim 1, characterized in that: The static cone penetration test rod reaction device (11) is installed in front of the engine system (3); the static cone penetration test rod reaction device (11) includes a static cone penetration rod body (10), and the lower end of the static cone penetration rod body (10) penetrates the loading platform (1).

3. The integrated machine for plate load, static cone penetration, spinning cone penetration, and dynamic cone penetration testing according to claim 1, characterized in that: The rotary pressing probe penetration reaction device (12) includes a rotary pressing probe (13), and the rotary pressing probe (13) penetrates the loading platform (1).

4. The integrated machine for plate load, static cone penetration, spinning cone penetration, and dynamic cone penetration testing according to claim 1, characterized in that: The power penetration test rod penetration reaction device (14) is located at the front end of the loading platform (1), including a power penetration test rod, a power penetration test hammer automatic unhooking and hammer lifting controller (15), a power penetration test hammer drop distance control device (16), and a power penetration test rod verticality maintaining device (17) fixed on the loading platform (1); the top end of the power penetration test rod is connected to the power penetration test hammer drop distance control device (16), and the lower end passes through the power penetration test rod verticality maintaining device (17).

5. The integrated machine for plate load, static cone penetration, spinning cone penetration, and dynamic cone penetration testing according to claim 1, characterized in that: The plate load test module (18) includes a load plate loading hydraulic cylinder.

6. The integrated machine for plate load, static cone penetration, spinning cone penetration, and dynamic cone penetration testing according to claim 1, characterized in that: The loading platform (1) is also equipped with a counterweight (6).

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