Field of the invention

[001] The present invention relates to a settlement plate system for measuring settlement of soil on a construction site, whereby the system comprises a base plate arrangement and a riser arrangement, riser arrangement being removable fixable to said base plate arrangement.

[002] The present invention relates to an apparatus for holding a position measuring device, in particular a measuring device for determining the height and position of a particular place on the ground.

Background art

[003] In order to measure the settlement of soil, for example at a building site, during roadway construction or during dyke construction, settlement plates are used for monitoring the settlement of the site’s soil. Such settlement plate consists of a base plate and a riser, which is also known as telltale or extension rod.

[004] Such a settlement plate is known from the utility model CN210684811U disclosing a settlement plate for a soft soil foundation. Belonging to the field of buildings, the utility model discloses a settlement plate for a soft soil foundation. Bottom plate, a bottom pipe is fixedly welded to the upper surface of the bottom plate. The surface of the upper end of the bottom pipe is fixedly connected with a connecting pipe through a connector; the outer surface of the bottom pipe and the outer surface of the connecting pipe are slidably sleeved with a protection pipe. The protection tube is a PVC tube. Supporting ribs are fixedly connected to the surfaces of the bottom pipe and the bottom plate; the lower end surfaces of the supporting ribs are fixedly welded to the bottom plate. The inner end surfaces of the supporting ribs are fixedly welded to the outer surface of the lower side of the bottom pipe, the supporting ribs are distributed on the peripheral surfaces of the bottom plate and the bottom pipe, the supporting ribs are of a triangular frame structure, sinking resistance is reduced, hexagonal grooves are formed in the connecting pipe and the connector, a wrench can be conveniently clamped, twisted and connected, and the connecting pipe can be conveniently fastened in the connecting process. Fig. 1, displays the settling plate disclosed in CN210684811U, including a bottom plate 1A, a bottom pipe 2A is fixedly welded on the upper surface of the bottom plate 1A, and a connecting pipe 4A is fixedly connected to the upper surface of the bottom pipe 2A through a connector 3A. The outer surface of the bottom tube 2A and the connecting tube 4A is slidingly sleeved with a protective tube 5A, and the protective tube 5A is a PVC tube. The bottom tube 2A is fixedly connected to the surface of the bottom plate 1A with a supporting rib 6A, and the lower end surface of the supporting rib 6A is fixedly welded to the bottom plate 1A. The inner end surface of the supporting rib 6A is fixedly welded to the lower outer surface of the bottom tube 2A. The supporting ribs 6A are distributed on the surrounding surfaces of the bottom plate 1A and the bottom tube 2A. The supporting rib 6A adopts a triangular frame structure, and the supporting rib 6A is provided with a triangle The opening 7A, the triangular opening 7A of the supporting rib 6A is provided with a triangular notch groove 8A, the lower outer end surface of the base plate 1A is provided with an annular notch groove 9A, the outer surface of the connector 3A is provided with a first hexagonal groove 10A, and the outer surface of the connecting pipe 4A is provided. The second hexagonal groove 11A.

[005] Another settlement plate is know from https://www.geokon.com/4625 and https://www.geokon.com/content/datasheets/4625_Settlement_Pl ate.pdf showing a settlement plate system which is designed primarily as an inexpensive means for monitoring in areas where significant settlement or substantial material displacement is expected. The system consists of a base plate and a reference rod (riser pipe) equipped with necessary threaded end connections enabling the pipe sections to connect to each other, as well as attach to the base plate. The system is further disclosed as having as the primary components a base plate, a reference rod and couplings for the rod. The base plate is typically constructed from a square, double thick, pressure treated plywood, however a steel plate may also be used in its place. The reference rod and couplings, female threaded on both ends, are composed of galvanized steel for maximum durability. The base plate is provided with a galvanized steel floor flange.

[006] Under normal circumstances, settlement plates are buried, mostly by sand, over the time of construction activities or preparations thereof. Once a settlement plate is buried deep in the ground, it is almost impossible to retrieve the system in a desirable way.

[007] To retrieve the complete system is only possible by using machinery like an excavator to dig a large and deep hole by removing the applied sand layers till reaching the level of the base plate, Thereafter the settlement plate system can be fully removed.

[008] If the contractor is obliged to remove the complete settlement plate system with all it’s riser pipes, a technical problem arise; The needed hole with about 5 meter diameter ranges between 2 and 10 meters deep and will act as a disturbance in the sand layer construction. The obtained stability of the applied sand layer on respective locations will be significantly disturbed and will not full-fill geotechnical soil stability requirements.

[009] Under construction law, there is often the obligation of the contractor to remove settlement plates from areas when the settlement monitoring came to a conclusion. However, usually, only a small portion of the riser can be removed without harming the sand layer construction as mentioned before. Furthermore, in case PVC pipe segments were used as a protective measure around the riser, as disclosed in CN210684811U, such PVC segments will remain in the soil. Under general sustainability assumptions, this is not desirable.

[0010] In the system of the prior art, it is impossible to remove the base plate after such settlement monitoring activities without harming the applied sand layer construction at the locations of the settlement plates. Therefore the before mentioned known systems will always leave parts of various materials in the soil which was monitored. Under some circumstances, the entire riser remains buried in said soil.

[0011] The present invention seeks to overcome the shortcomings of the previously known systems by providing a settlement plate system which allows for the complete removal of all parts, with the exception of the base plate. However the base plate of the present invention is made from environmentally friendly materials which is bio-degradable and can be broken down by nature over time.

[0012] Measuring heights and positions of portions of a landscape is well known in the field of geological monitoring. Patent document US2020/0326187A1 discloses a monitoring method wherein: a target is prepared using terrain model data including terrain location information; at a first time, an image of the target is picked up by means of an image pickup unit of a surveying device, and first image data is generated; at a second time after the first time, an image of the target is picked by means of the image pickup unit of the surveying device, and second image data is generated; and displacement of the target is detected using a first image based on the first image data, and a second image based on the second image data. The system of US2020/0326187A1 employs GNSS receivers to determine if the position of a location to be monitored has changed.

[0013] High grade RTK GNSS receivers for position monitoring are commonly used to measure a beacon which are anchored to the ground and allow, by means of an riser, a GNSS receiver to be held in/at a certain height, such that GNSS constellations can be received. Such an apparatus, known as a settlement plate, suitable for holding a measuring device, such as a GNSS receiver is known from https://www.geokon.com/content/datasheets/4625_Settlement_Pl ate.pdf. This online document describes a settlement plate having a base plate made from plywood or steel and a modular riser. Said modular riser consists of riser segments and coupling means. Said riser segments having a length of 152.4 centimeters (5 feet) and are threaded at the ends, however grains and sand may be trapped in the male threaded ends, connecting them by hand delivers inaccurate extension. To assemble the riser to the required distance between the base plate and the measuring device couplings are screwed onto the threaded ends of the riser segments. The riser can therefore vary in length by steps of 152.4 cm, the length of an individual riser segment.

[0014] Alternatively “squared flanges” settlement plates are commonly used in the Netherlands known from https://zakbaken.nI/wp-content/uploads/sites/5/2021/09/LMW-Z akbaken.pdf, flanges are welded at both ends of an pipe segment, flanges are connected with four bolts one at each corner of the flange known from https://zakbaken.nl/wp-content/uploads/sites/5/2021/09/LMW- Oplenger.pdf. These flange riser segments can vary in length between 100 cm and 200 cm, the length of an individual riser segment.

[0015] For the flange risers more metal material is used in order to construct the squared flanges at both ends, therefore flange risers are more heavier to operate compared to threaded risers with equal length.

[0016] In order to extend the riser to the required length, a fieldworker therefore have to be supplied with a sufficient amount of riser segments, couplings or bolts (in case of the “squared flanges” risers).

[0017] Furthermore, unused riser segments, couplings or bolts will have to be collected and stored after the installation of the settlement plate.

[0018] Settlement plates are commonly use in a bed of sand and sand is packed on top of the base plate, which is placed on the ground. In case of the threaded end riser segments the presence of sand can pose difficulties to screw the couplings to the threads of the riser segments, potentially leaving a weak connection between the coupling and the riser segments.

[0019] Should grains of sand accidentally be trapped in the threads of the couplings or the riser segments when it’s installed, it might be impossible to screw the next riser on top of it, rendering the riser segments unsuitable for future use.

[0020] The known apparatus, for reason of the modularity of the risers, does not allow for a compact transport of the entire device as a single entity.

[0021] The default baseplate riser in combination with one or more riser(s) results in the complete settlement plate construction.

[0022] The complete settlement plate construction is categorized as “single use system”. When the settlement monitoring came to a conclusion (end of use) a significant part of the settlement construction is left behind into the soil. Between 80 and 90% of it’s raw material is lost after use.

[0023] The present invention seeks to overcome the above mentioned shortcomings of the previously known riser types as part of the settlement plate system.

Summary of the invention

[0024] According to the present invention, a settlement plate system is proposed which employs a bayonet-like connection between a base plate having an aperture and a riser. Said bayonet-like connection allows for effortless decoupling and removal of the riser from the base plate. The decoupling requires a quarter turn to disengage the locking element.

[0025] The solution of the present invention is based of a locking mechanism employing a locking member fixed to the riser and various abutment and engagement surfaces at the base plate.

[0026] A further aspect of the present invention is the use of environmentally friendly materials, in particular for parts of the settlement plate system which cannot be retrieved and therefore remain in the soil.

[0027] One embodiment of the present invention comprises the base plate with the aperture, wherein the baseplate is further provided with at least one recess forming abutment surfaces for the locking member.

[0028] In an alternative embodiment, the abutment surfaces are formed by at least one stopper block, wherein said stopper block is mounted to the lower surface of the base plate.

[0029] Further embodiments of the invention employ a bearing or guiding block which provides guidance to the lower part of the riser, thereby increasing the stability of the system. The bearing block further encloses the locking mechanism, thereby reducing the risk for sand of other soil matter to foul the locking mechanism.

[0030] Another aspect of the present invention is the use of bio-degradable materials for parts which will be left in the soil. Such materials are selected from the following list: wood, bamboo, plywood, bio-degradable plastics, biodegradable medium density fibreboard, or a combination thereof. [0031] Another aspect of the present invention is the material used for the riser. Preferred materials for the riser need to be abrasion and corrosion resistant as well as strong in respect to tension and torsion. The riser of the present invention is therefore made from materials of the following list: steel, stainless steel, aluminium, carbon fibre composites, fibreglass composites, or a combination thereof.

[0032] According to the present invention, a holding apparatus as defined above is provided, in which the riser is telescopic and fully reusable.

[0033] A telescopic riser, when retracted, is a single unit having a length of approximately 2 meters made from a lighter material such as aluminum and/or recyclable polyesters.

[0034] Should a more compact unit be required, the telescopic segments can be chosen such that the needs of the user and the desired local occupational health and safety regulations can be accommodated.

[0035] One advantage of the telescopic riser according to the present invention is that the telescopic arrangement contains all segments to accommodate the desired maximum length of about 6 meters. A fieldworker therefore will only be provided with a single entity riser in order to install the holding apparatus. In operation a fieldworker, crane operator or bulldozer operator is able to extend the telescopic riser which results in less or no extra transport movements of traditional single use risers. Of course it is conceivable to construct the telescopic riser such that longer riser extensions will be possible.

[0036] Additionally to the previously mentioned advantage, no unused parts will be in the field and therefore neither collection nor storage of such parts will be required.

[0037] A further advantage of a telescopic riser is that, when retracted, only the outer most, or lowest, segment is exposed to the elements, such as water and sand, thereby protecting the other telescopic segments. Therefore, no grains of sand can enter the interface between the telescopic segments. Consequently, sand will not be causing difficulties installing and operating the holding apparatus of the present invention.

Brief description of the drawings

[0038] The present invention will be discussed in more detail below, with reference to the attached drawings, in which:

[0039] Fig. 1A depicts a settlement plate according to the prior art.

[0040] Fig. 2A depicts the base plate of the settlement plate of the present invention.

[0041] Fig. 3A depicts the stopper block of the settlement plate of the present invention.

[0042] Fig. 4A depicts the guide or bearing of the present invention.

[0043] Fig. 5A depicts a rendering of the riser of the present invention.

[0044] Fig. 6A depicts a rendering of a simplified base plate with stopper blocks as view from below.

[0045] Fig. 7A depicts a schematic view of the settlement plate assembly, without the bearing block, in the unlocked position from below.

[0046] Fig. 8A depicts a side cut view of the settlement plate system, the riser being in the locked position. [0047] Fig. 9A depicts a side cut view of of an alternative embodiment of the settlement plate system, the riser being in the locked position.

[0048] The present invention will be discussed in more detail below, with reference to the attached drawings, in which:

[0049] Fig. IB depicts a settlement plate system according to the prior art.

[0050] Fig. 2B depicts a settlement plate system according to the present invention.

[0051] Figs. 3B-a and 3B-b depict a telescopic coupling according to the present invention.

[0052] Fig. 4B depicts a cross section of the telescopic coupling according to the present invention.

[0053] Fig. 5B depicts a cross section of an alternative embodiment of the telescopic coupling according to the present invention.

[0054] Fig. 6B depicts the fastening means of the alternative embodiment of the telescopic locking mechanism.

[0055] Figs. 7B-a to 7B-f depict the use of a settlement plate system according to the present invention.

Brief description of best mode of the invention

[0056] The preferred way to carry out the present invention involves a base plate arrangement to which a riser arrangement can be locked and unlocked by a quarter turn of the riser. This allows the riser arrangement to be unlocked from the base plate arrangement, even if the base plate arrangement is deeply buried in sand or soil and therefore no longer accessible. It is an objective of the invention to allow the entire riser arrangement to be extracted when the settlement monitoring is concluded. This way, the only part that will remain in the soil after the settlement monitoring will be the base plate arrangement.

[0057] Therefore, in the preferred embodiment the base plate arrangement is made of a biodegradable material such as wood or bamboo. Further, the base plate arrangement and its components may also be made of biodegradable medium density fibreboard or biodegradable plastic materials. Also, a combination of the above mentioned materials can be conceived.

[0058] Further, in the preferred embodiment, see Fig.2A, the base plate arrangement is foreseen with a base plate 20A having a central aperture 21A. Said central aperture has a shape of an oblong, a rounded rectangle or a rectangle. An oblong, in this invention, is defined as two semicircles connected by a rectangle.

[0059] The oblong shaped aperture, in the preferred embodiment, has a longest length (major axis) being at least 1.5 times or preferably but not limited to 2 times the length of the shortest length (minor axis).

[0060] The base plate arrangement 70A of the preferred embodiment, as shown in Fig.7A, is further foreseen with at least one engagement surface 75A in the vicinity of the shortest dimension of the aperture. In other words, the at least one engagement surface is located next to the centre of the base plate 70A and next to the rectangle connecting the two circles of the oblong. Said at least one engagement surface 75A will lock the riser arrangement 72A, 77A to the base plate 70A in the locked position of the riser arrangement, when a locking member 72A of the riser arrangement is rotated 79A into the locked position.

[0061] The base plate arrangement of the preferred embodiment is further foreseen with at least two abutment surfaces 73A, 74A. Said abutment surfaces define the open and closed position of the locking mechanism locking the riser to the base plate.

[0062] The abutment surfaces can be provided by at least one stopper block (30A, 69A). A stopper block can be a single block of material, see Fig. 3A, or several independent part, as shown in Fig.6A. The stopper block (30) of Fig. 3A provides a cut-out (31A) in which the locking element of the riser arrangement is accommodated when the settlement plate system is deployed. The stopper block (30A) provides at least one abutment surface (34A) for the unlocked position and at least one abutment surface (33A) for the locked position.

[0063] The riser arrangement 52A, 55A, 56A, 57A of the preferred embodiment of the settlement plate system, see Fig.5A, is made from a corrosion resistant material such as steel, stainless steel, aluminium, carbon fibre composites, fibreglass composites, or similar such materials. The riser arrangement is depicted up-side down in Fig.5A.

[0064] The riser arrangement of the preferred embodiment consists of four functional parts, an upper riser portion 55A, a middle portion 56A, a locking member 52A and a lower riser portion 57A. The locking member is fixed between the middle riser portion and the lower riser portion.

[0065] The upper riser portion can be connected to extension rods, as commonly known in settlement plate systems. The upper riser portion 55A has a diameter which is at least as big as the longest dimension of the aperture in the base plate, in other words, the diameter of the upper riser portion is at least the length of the longest dimension of the oblong, as mentioned above. With a diameter of the upper riser portion’s abutment surface 59A being greater than the largest length of the central aperture 61A of the base plate 60A, the upper riser section forms a lid, thereby closing the central aperture, which prevents sand or soil to enter the locking mechanism from above.

[0066] With a diameter of the upper riser portion 85A greater than the longest dimension of the oblong, the upper riser portion 85A will also have a diameter greater than the widest extension of the locking member 82A. This is an important feature when the riser arrangement is to be removed after completion of the settlement monitoring. In such an arrangement, the larger diameter of the upper riser 85A, against which the sand or soil pack rests, the upper riser 85A prevents the locking element 82A to catch the sand or soil pack. Therefore, the locking element 82A will not hinder the removal of the riser arrangement.

[0067] In the preferred embodiment, the middle portion 56A of the riser has a diameter less than the shortest length of the aperture in the base plate, as mentioned above. The middle portion of the riser can rotate freely in the aperture of the base plate, but is guided by the aperture. Therefore, the diameter of the middle portion of the riser is greater than 0.5 times the shortest length of the aperture’s oblong.

[0068] The middle section 56A of the riser arrangement has a length which corresponds with the thickness of the base plate 60A at the location of the central aperture 61A. This ensures that the base plate 60A at the location of the central aperture 61A is securely placed between the abutment surface 59A of the upper riser portion and the locking element 52A. However, the dimensions need to be chosen such that the riser arrangement, when inserted to the base plate arrangement, can be rotated.

[0069] The locking element 52A of the preferred embodiment has an oblong shape, such as to fit through the aperture in the base plate in the unlocked position. Therefore, the dimensions of the locking member are smaller than the dimensions of the aperture 61A in the base plate 60A, shown in Fig.6A. However, the longest dimension of the locking element 52A is longer than the shortest dimension of the aperture, such that the locking member overlaps with the at least one engagement surface 65A of the base plate 60A, thereby locking the riser arrangement to the base plate.

[0070] In the preferred embodiment, the lower riser portion 57A extends beyond the locking element 52A. The lower riser portion, since it extends beyond the base plate, is pushed into the ground when the settlement plate system is installed. The lower riser portion 57A thereby provides initial stability before the first deposition of sand or soil on top of the base plate.

[0071] The preferred embodiment of the settlement plate arrangement can optionally be provided with a bearing block 40A, as shown in Fig.4A. Said bearing block 40A is provided with a through- hole 49A in which the lower riser portion 57A can be accommodated. The bearing block 40A will thereby provide guidance to the riser arrangement. The bearing block 40A will also provide a certain protection to the locking mechanism by forming a barrier for soil or sand to enter the locking mechanism.

[0072] Fig. 8A depicts a base plate arrangement having a base plate 80A with a central aperture 81A, a stopper block 83A and a bearing block 84A.

[0073] Fig. 8A further depicts a riser arrangement 82A, 85A, 86A, 87A, 88A being inserted into the base plate arrangement 80A, 83A, 84A in a locked position. Fig. 8A shows that the upper riser section 85A abuts against the upper surface of the base plate 80A. With upper riser portion 85A resting on the base plate 80A, the riser arrangement is held perpendicular to the base plate arrangement. Further, the upper riser portion, by resting on the base plate 80A over the central aperture 81A, the upper riser portion 85A acts as a lid, thereby protecting the central aperture 81A from sand or soil.

[0074] The middle riser section 86A is accommodated inside the central aperture 81A of the base plate 80A.

[0075] The locking member 82A is engaged in a locked position and abuts against the lower surface of the base plate 80A. The locking element is accommodated inside cut-out the stopper block 83A.

[0076] The lower riser portion 87A is accommodated by the bearing block 84A. Said bearing block 84A closes the cut-out of the stopper block 83A, thereby preventing soil to enter into the locking mechanism from below.

[0077] The present invention seeks to overcome the shortcomings of the prior art by using a telescopic riser. Said telescopic riser is part of the DeltaCube Total Settlement System, DeltaCube TSS”. In this document, the term DeltaCube refers to a measurement unit, mounted on top of the outer riser. The DeltaCube is a solar powered GNSS measuring sensor device, with the size of half a football, which is able to measure position differences at cm/mm scale of accuracy.

[0078] The telescopic riser consists of one or more, up to ten risers of essentially equal length of between 1 cm and 400 cm. Each riser segment has a slighter smaller inner diameter between 1 mm and 50 cm, such that the riser segments fit tight in each other resulting in a telescopic riser mechanism.

[0079] The base plate is made from wood or any other biodegradable material. The center of the base plate contains an oval opening which is entered by the riser. The lowest end of the telescopic riser consists of a small riser 1 till 30 mm riser diameter which act as an soil anchor to stabilize the riser on top of the ground. More details about the geometry of the base plate and the lower portion of the riser are disclosed in a prior patent document by the applicant, which is hereby incorporated by reference patent application: 2033261.

[0080] Installing the base plate (71B) is done by laying down the base plate on top of the the ground (74B), as shown in Fig. 7B-a. Four struts (26B) are inserted and smashed into the base plate by means of a rubber mallet. The four struts are positioned in four quarters with a 90 degree angle. The four struts (26B) are hold together by a circular wooden or biodegradable fixation plate (27B) on top of the four struts, as shown in Fig. 2B.

[0081] In a second step, as shown in Fig. 7B-b, the riser assembly (72B) is inserted through the opening of the the fixation plate (27B) and created space by the four struts (26B) and eventually through the base plate (21B) itself into the soil. The riser will be locked by turning the complete riser by 90 degrees, as disclosed in the above mentioned prior patent application: 2033261.

[0082] In a third step, as shown in Fig. 7B-c, the first sand layer (75B) is added on top of the base plate. When the sand layer reach the height of 1 meter, relative to base plate, the field worker will raise the second riser segment.

[0083] When the sand layer (74B) reach the height of 2,5 meter, the fieldworker will raise the third riser segment to it’s final extendable length, as shown schematic in Figs. 7B-d and 7B-e. The riser segments will be connected by one or more up to ten locking pins. Said locking pins pass through both pipe segments as shown in figures 3B to 5B.

[0084] The riser segments may be applied with a marker scale, such that a fieldworker is able to obtain (read) the sand layer height relative to the base plate outside and to obtain the number of sand layers relative to the base plate.

[0085] A decoupling riser is directly connected on top of the base plate with a decoupling mechanism. At the outer top riser a adapter mounting , a hexagonal bracket is used to connect the a (sensor) measurement device by means of the telescopic riser. Said sensor device is know as “DeltaCube”. Both orientations of the telescopic riser, upside-down or downside-up, are used. The particular orientation will depend on the soil structure and type of soil.

[0086] Each riser is able to connect with manual removing tools. Two different manual tools will be used. The first manual tool is a rotating bar to allow to rotate the complete risers entity turned up and out of the sand layers. The second manual tool is a lever tool to allow the complete riser entity to be lifted up and out of the sand layers. Both tools will be submitted to this patent at a later stage.

[0087] DeltaCube TSS installation and demobilization part is done by using an electrical 4x4 driven vehicle. This vehicle is provided with a custom made transport box with raster sized compartments of 1 by 30 cm (length x width). Said transport box is adapted for transporting the telescopic risers. Below the compartments at each side of the vehicle a pull-out drawer is mounted. Said pull-out drawer is adapted to transport the wooden or biodegradable base plates together with the struts and fixation plates.

[0088] Said decoupling or locking lip mechanisms may include bayonet coupling means, as disclosed in the above mentioned prior patent document: 2033261 by the applicant. The decoupling or locking lip mechanisms can be made from iron, steel, stainless steel or any other suitable metallic material. Further, the decoupling or locking mechanisms can also be made from suitable hard plastics.

Description of embodiments

[0089] In a first alternative embodiment, see Fig. 9A, a base plate 90A is provided with a central aperture 91A and a recess 99A which forms at least two abutment surfaces and at least one engagement surface.

[0090] In this embodiment, the central aperture 21A, 91A is shaped in the form of an oblong, as depicted in Fig. 2A. This allow the passage of the locking element 92A in the unlocked position.

[0091] The recess 99A in the base plate 90A has shape similar to the shape of the cut-out 31A in the stopper block 30A, as shown in Fig.SA. Thereby the recess will form the abutment surface of the unlocked position 34A and the abutment surface for the locked position 33A.

[0092] The recess 99A has a depth such to be able to accommodate the locking element 92A, still allowing to the rotation of the riser assembly, see Fig. 9A, which depicts the first alternative embodiment in the locked position.

[0093] Similarly to the preferred embodiment, an optional bearing block 40A, 84A can be mounted to the lower surface of the base plate. This bearing block provides additional stability to the riser arrangement 92A, 95A, 96A, 98A. The bearing block 94A also closes the space for the locking mechanism formed by the recess 99A.

[0094] In a section alternative embodiment, see Fig. 10A, the base plate 100A is provided with the central aperture 21A, 101A in form of an oblong, as depicted in Fig. 2A. Similar to the first alternative embodiment, a first recess 109A is formed to provide at least two abutment surfaces and at least one engagement surface. The first recess 109A has a depth proximately equivalent to the locking element 102A, still allowing the riser assembly to be rotated.

[0095] In the second alternative embodiment, a second recess 110A is formed, shallower than the first recess 109A. Said second recess 110A has the shape of the bearing block 40A, 104A, as depicted in Fig. 4A. Said second recess 110A preferably has the depth equivalent to the thickness of the bearing block 104A, so that the lower surface of the bearing block 104A is flush with the lower surface of the base plate 100A. [0096] In Fig. 10A, the second alternative embodiment is depicted employing dowels 111A in order to mount the bearing block 104A into the recess 110A of the base plate 100A. Using dowels, in particular wooden dowels, is commonly known, however, such wooden dowels provide an advantage not commonly recognised. In a moist environment, wood will swell to a certain extend. With the proper combination of types of wood or bamboo, the wooden dowel will swell over time and thereby strengthen the connection between the parts. While dowels are only depicted in the second alternative embodiment, dowels would a suitable option of all embodiments of the present invention.

[0097] The second alternative embodiment, having a flush surface can easily be piled and stored. Further, the locking mechanism is protected from ingress of sand or soil, when installed.

[0098] The base plate 20A, 60A, 80A, 90A, 100A of all embodiments has a dimension from about 30x30 cm ² to about 2x2 m ² , depending on the environment and circumstances of the settlement monitoring. Under practical considerations, smaller base plates are easier to transport, handle and install. However, a smaller base plate may not offer the initial stability required for the system. Large base plates, in contrast, do provide better initial stability, will be however difficult to handle and install, in particular with a smaller crew. The most preferred dimension for the base plate is therefore considered being between 50x50 cm ² and lxlm ² .

[0099] The base plate 20A, 60A, 80A, 90A, 100A of the settlement plate system will remain in the ground. Therefore, the base plate is made of a material which is biodegradable over time and not harmful for the environment. A preferred material for the base plate is therefore wood, in particular from fast growing trees, such as eucalyptus or pine. Another preferred material for the base plate is bamboo.

[00100]The base plate can also be made from wood based materials, such as biodegradable medium density fingerboard (MDF) or biodegradable plywood.

[00101]The base plate can also be made from biodegradable plastic materials. Using such materials has the benefits of mass production methods such as moulding or additive manufacturing. Compared to the above mentioned natural materials, the base plate can be manufactured without creating scrap materials such a wood dust and shavings. Therefore, base plates made from biodegradable materials can be seen are potentially more environmentally friendly.

[00102]The base plate 20A, 60A, 80A, 90A, 100A is provided with an aperture 21A, 61A, 81A, 91A, 101A in shape of an oblong, a rounded rectangle or a rectangle. When using wood, bamboo or a wood based material, the manufacturing of the base plate requires an aperture to be cut into the centre portion of the base plate. Hereby, an aperture with the shape of an oblong has the advantage a easy creation by drilling two through-holes and cutting out the material in between the two through-holes.

[00103]The oblong shape can also be created easily by a drill mill process, in which a drill-mill bit is lowered at one end of the oblong to be created in a first step, moved to the other end of the oblong to be created in a second step and pulled up in a third step. [00104]Any other suitable shapes can be used, however, such other shapes might need fabrication methods such as laser-cutting or water-jet-cutting. Laser-cutting can provide an additional advantage of burning markings, drawings and/or instructions into the surface of the base plate. Such markings, drawings and/or instruction can help the assembly and installation process of the settlement plate system, thereby improving the reliability of the installation.

[00105]The at least one engagement surface 25A, 65A of the base plate, as shown in Fig. 2A and Fig. 6A, is not a particular separate physical item but rather an area of a surface on the base plate 20A, 60A. This area can be either on the bottom surface of the plate, or, in further embodiments, be formed by a recess in the base plate. Said recess of the further embodiments can be formed either my milling, when using a wood or bamboo based material. The recess of the further embodiments can also be formed by moulding or by additive manufacturing (AM), when a plastic material is used for the base plate.

[00106]The base plate 60A, 70A is further foreseen with abutment surfaces 33A, 34A, 63A, 64A, 73A, 74A, as shown in Fig. 6A and Fig.7A. Said abutment surfaces 73A, 74A, as shown in Fig.7A, will stop the rotation 79A of the riser arrangement 72A, 77A when the locking element 72A of the riser arrangement abuts against one of the abutment surfaces 73A, 72A. A rotation in a particular direction is stopped when the locking element 72A abuts against the abutment surface of either the open or unlocked position or the closed or locked position. In the open position, as shown in Fig.7A, the riser arrangement can be moved through the aperture of the base plate 70A. In the closed or locked position, after the riser arrangement has been rotated 79A, with the locking element engaging with the at least one engagement surface 75A of the base plate 70A, the locking element is engaged with the engagement surface 75A and therefore the locking element prevents the riser arrangement to be moved out or pulled out of the aperture in the base plate 70A, hence, the riser arrangement is in a closed or locked position.

[00107]The abutment surfaces 33A, 63A, 34A, 64A can also be provided by at least one stopper block 30A, 69A, as shown in Fig.3A and Fig.6A. Said stopper block is permanently fixed to the lower surface of the base plate 20A, 60A adjacent to the aperture 21A, 61A in the base plate. Said stopper block is made from a biodegradable material selected from the list of wood, plywood, bamboo, MDF, biodegradable plastics or similar materials.

[00108]The at least one stopper block 30A, 69A is adhered to the lower surface of the base plate (20A, 60A) by means of a, preferably an environmental friendly, adhesive or by form fitting, for example with wooden dowels as known from furniture manufacturing. Form-fitting has the added advantage of not having an additional substance which might influence the environment over time. The combination of glueing with an adhesive and form-fitting adds strength to the base plate arrangement by the use of a small amount of adhesive.

[00109] Form-fitting construction with dowels ensure that the stopper block is correctly aligned when the stopper block is fixed to the lower surface of the base plate. Said dowels can be wooden dowels or dowels made from any other suitable biodegradable material.

[00110] Form-fitting construction can be achieved even more easily when the parts of the base plate arrangement are manufactured by moulding or AM. [00111] In order to help the process of aligning the stopper block with and fixing the stopper block to the base plate by adhesion only, the base plate can be provided with markings or line-outs indicating the correct position of the stopper block. Said markings and outlines can be burnt in with a laser burning or cutting machine.

[00112] In a first alternative embodiment, see Fig. 9A, the abutment surfaces can also be provided by a recess 99A in the base plate 90A. Said recess can be formed my milling, when using a wood, plywood, MDF or bamboo based material. The recess can also be formed by moulding or by AM, when a plastic material is used.

[00113] In this alternative embodiment, the at least one engagement surface is formed by the milling process. The at least one engagement surface is thereby the milled out surface which is coplanar to the lower surface of the base plate. The locking element 92A engages with the engagement surface in the recess in order to lock the riser assembly 92A, 95A, 96A, 97A, 98A, as shown in Fig.9A.

[00114]The advantage of the alternative embodiment, all surfaces relevant to the locking mechanism are created in a single manufacturing step. The alternative embodiment therefore provides a simplified manufacturing process of the locking mechanism.

[00115]A further advantage of the alternative embodiment is that manufactured base plate arrangement can easily piled, since no features extend beyond the base surfaces of the base plate.

[00116]The diameter of the upper riser portion 85A, 95A, 105A is between 1.5 cm and 20 cm, depending on the environment and circumstances of the settlement monitoring. However, said diameter is matched to the dimensions of the base plate and the aperture therein. In general, the diameter of the upper riser portion is greater than the longest distance in the aperture.

[00117] Diameter of the lower middle and riser portions between 0.5 cm and 10 cm, depending on the environment and circumstances of the settlement monitoring.

[00118]The lower portion 57A, 87A, 97A, 107A can be provided with a tapered tip 88A, 98A, 108A. Such a tapered tip will help to insert the lower riser portion into heavier soil.

[00119]The shape of the locking element 52A, 72A, 82A, 92A, 102A corresponds to the shape of the central aperture 21A, 61A, 81A, 91A, 101A. While the shape of the central aperture 21A, 61A, 81A, 91A, 101A and the locking element 52A, 72A, 82A, 92A, 102A also could be rectangular, to provide the functionality described above, it is advantageous for the locking element to have no sharp edges, as sharp edges pose risk of injury to field workers. Therefore it is preferred that the shape of the locking element is either an oblong or a rounded rectangle.

[00120] While Fig. 7A depicts a counter-clockwise rotation 79A of the upper riser portion in order to lock the riser arrangement 72A, 77A to the base plate arrangement 70A, the arrangement can also be built such that a clockwise rotation of the upper riser portion would lock the arrangements together. The choice of direction of rotation is given by other circumstances, such as the type of extension rods used in the settlement monitoring.

[00121]The part of the riser assembly can be made from any corrosion and abrasion resistant material. When using metal, such as steel, stainless steel, aluminium or brass, the individual parts can be manufactured separately and welded together or fabricated by a lathe and corresponding fabrication methods.

[00122]The riser assembly can however also be fabricated from modern composite materials such a carbon fibre composites of fibreglass composites. Modern composite materials have the advantage of allowing to strengthen some parts of the construction by adding more reinforcement, compared to other parts of the construction. Therefore, in particular parts of the riser arrangement can be designed to a similar loud bearing capabilities than other parts of the riser arrangement having lager diameters.

[00123] Depending on the materials used for the fabrication of the riser arrangement, an abrasion resistive coating can be applied to the riser arrangement. Such a coating will reduce the friction between the sand pack and the riser, which commonly is done by placing a PCV tube around the riser, as described in CN210684811U. The anti-abrasive coating further helps a smooth motion of the riser arrangement during unlocking of the riser arrangement by a quarter turn. Said quarter turn should be sufficient to overcome the friction between the riser arrangement and the sand pack. Therefore the anti-abrasion coating will also aid the full removal of the entire riser and riser arrangement.

[00124] Further aspects of the present invention is the use of materials of environmental friendly materials, such as wood, eucalyptus wood, bamboo and some hard biodegradable plastics like Polyhydroxyalkanoates (PHAs) and Polylactic acid (PLA).

[00125]Fig. 2B shows a perspective side-view 20B of the base plate assembly and the telescopic riser assembly.

[00126] In a preferred embodiment, as shown in Fig. 2B, a riser arrangement is mounted to a base plate assembly, which consists of a base plate 21 B, a plurality of struts 26B and a fixation plate 17B. Said riser arrangement comprises a soil anchor 29B, a mid section and a telescopic riser. The telescopic riser comprises a plurality of riser segments 22 B and 24B. Said riser segments of the plurality of riser segments, are made from hollow tubes, such that a riser segment with a smaller diameter can be coaxially inserted into a riser segment having a larger diameter.

[00127]To prevent the larger diameter riser segments for slide away, the inner smaller diameter segments can be provided with a stop at the outer surface. Such a stop, not shown in the figures, will help a field-worker to extend the telescopic riser.

[00128] For transport and primary installation, all riser segments of a telescopic riser are placed within the largest diameter riser segment, similar to a not-extended telescopic antenna. This allows for easy of transportation and handling.

[00129] Figs. 3B-a and 3B-b show perspective side views 30B of the locking mechanism of the telescopic riser.

[00130] In order to extend the telescopic riser from its original primary installation, see Fig. 3B-a and Fig 3B-b, the riser segment(s) 34B with diameters greater than the smallest riser segment 32B will be pulled upwards, until a marker 38B indicates the correct height for the extension of the telescopic riser. The outer riser segment 34B is held in its position by a locking pin 36B. Said locking ping 36B is itself held into position my holding means 35B.

[00131] In the preferred embodiment, the smallest diameter riser segment is located at the lowest point, that is close to the base plate assembly. With the thinnest riser segment at the base plate, the telescopic mechanism is protected from the ingress of sand between the riser segments.

[00132] It is further advantageous in the preferred embodiment, that extending the riser will loosen the packing and friction between the telescopic riser and the sand pack. This aids the removal of the riser after the measurement campaign has concluded.

[00133] Fig. 4B shows a cut view 40B of the locking mechanism of the telescopic riser.

[00134] In the preferred embodiment, see Fig. 4B, the holding member 45B is made from a material having resilient properties, such as steel of fibre reinforced plastic. The holding member of this embodiment will have end shapes 47B at both ends, such to help pushing the holding member over the outer riser segment 44B.

[00135]With the locking pin in place, the inner riser segment 42B and the outer riser segment 44B are locked.

[00136]The holding pin 46B can be made from any material strong enough to carry the load of the telescopic riser and the measurement unit on top of the riser. The pin can be made from steel, stainless steel, aluminium or fibre reinforced plastic.

[00137] In the preferred embodiment, the locking pin is integrally fixed to the holding member by any suitable method, such as welding, soldering or glueing.

[00138]Fig. 5B shows a cut view 50B of an alternative locking mechanism of the telescopic riser.

[00139] In an alternative embodiment, as shown in Fig. 5B, the holding member in a hook-and- loop fastener 55B, such as velcro strap. In this alternative embodiment, the locking pin 56 B and the holding member are two separate entities. In order for the locking pin 56 B to engage with the holding member 55B, the locking pin is supplied with a head 57B. Said locking pin is placed through an aperture 53B in the holding member 55B.

[00140]With the locking pin in place, the inner riser segment 52B and the outer riser segment 54B are locked.

[00141] Fig. 6B displays a top-view 60B of the holding member.

[00142]As shown in Fig. 6B, the aperture 63B of the holding member 65B, is placed at one end of the holding member. This aperture has essentially the same diameter as the locking pin 56 B. The head 57B of the locking pin has a larger diameter than the aperture. Therefore, the holding member will be held in place by the locking pin before engaging the holding member.

[00143] In order to hold the locking pin in place, the holding member 55B, 65B will be wrapped around the outer riser segment 54B and the locking pin 56B, as shown in Fig. 5B. Wrapping the mounting member of the alternative embodiment at least twice around the riser segment will cover both ends of the locking pin 56B, thereby protecting said pin from the environment.

[00144]A further advantage of the alternative embodiment is the ease of storage of the locking pins and holdings members.

[00145] List of reference signs IA, 9A = base plate of the prior art

2A = riser of the prior art

3A= riser connector of the prior art

4A = riser extension of the prior art

5A = protective PVC tube of the prior art

6A = support rib of the prior art

7 A = opening in the support rip of the prior art

10A, 11A = hexagonal groove in the settlement plate system of the prior art

20A, 60A, 80A, 90A, 100A = base plate

21A, 61A, 81A, 91A, 101A = aperture in the base plate

25A, 65A = engagement surface I zone I area

27A = area for the stopper block(s)

30A, 69A, 83A = stopper block

31A = cut-out in the stopper block

33A, 63A, 73A = abutment surface for the locked position

34A, 64A, 74A = abutment surface for the unlocked position

40A, 84A, 94A, 104A = bearing / guide block

49A = through whole in the bearing I guide block

52A, 72A, 82A, 92A, 102A = locking element

55A, 85A, 95A, 105A = upper riser portion

56A, 86A, 96A 106A = middle riser portion

57A, 77A, 87A, 97A, 107A = lower riser portion

59A = upper riser abutment surface

79A = direction of engagement action

88A, 98A, 108A = tapered tip

99A, 109A = recess in base plate forming at least one abutment surface

110A = recess for bearing I guide block

111A = dowel

IB.21B, 71B = base plate

2B, 22B, 32B, 42B, 52B = first riser segment

3B = riser coupling

4B, 24B, 34B, 44B, 54B = second riser segment

5B = protective sleeve

6B, 26B = base plate mounting struts

20B = settlement plate assembly

27B = fixation plate

29B = soil anchor

30B = telescopic coupling front view

31B = telescopic coupling rear view 35B, 45B, 55B = holding member

36B, 46B, 56B = locking pin

38B = alignment marker

40B, 50B = cross section of the telescopic coupling 47B = spring guide

60B = alternative fastening means

63B = opening for the locking pin

65B = hook-and-loop fastener, velcro strap