The present invention relates to the anchoring system for inflation operated bottom hinged water control gates. Such gates may be used, for example, for water storage, river diversion, hydropower impoundments, flood control, sea water barriers, spillway control, and the like.
Prior art bottom hinged water control gates include gates operated by hydraulic cylinders from above, gates operated from hydraulic cylinders from below, gates operated by torque tubes extending into piers or abutments, overhead hoist operated gates, as well as pneumatically actuated bottom hinged gates.
Inflation operated water control gates are well known. Prior art includes U.S. Pat. No. 4,780,024 to Obermeyer et al; U.S. Pat. No. 5,092,707 to Henry K. Obermeyer; U.S. Pat. No. 5,538,360 to Henry K. Obermeyer; U.S. Pat. No. 5,642,963 to Henry K. Obermeyer; U.S. Pat. No. 5,709,502 to Henry K. Obermeyer; U.S. Pat. No. 5,713,699 to Obermeyer et al. Such inflation operated water control gates generally incorporate an inflatable bladder for actuation in conjunction with a reinforced elastomeric hinge to pivotably secure each gate panel along its lower edge. It should be noted that the preceding description is for a typical gate. Other examples may be located within a closed conduit and mounted in an inverted position with the hinge on top so as to be able to discharge sand, for example, without obstruction of the hinge mechanism by the sand being controlled. Inflation operated gates in accordance with the aforementioned prior art require that the anchor bolts carry, not only vertical tensile loads, but also shear and bending loads in the horizontal upstream-downstream direction while the concrete surrounding these anchor bolts is subjected to corresponding horizontal loads.
The present invention relates to an improved inflatable bladder and hinge flap clamping and retention means.
As is generally the case for structures subject to gravitational loads, the stresses in water control gates increase in proportion to gate height, if the proportions of the gate are simply scaled with height. As anchor bolts are scaled with height in order to hold stress levels constant, the large diameter-to-spacing ratio that results as gate system height is increased from 3 meters to 8 meters, for example, results in heavy large diameter anchor bolts, nuts and washers and heavy clamp castings. Long term serviceability of the gate system requires protection from corrosion. The cost of using stainless steel for the anchor bolts and associated nuts and washers increases with damming height. These costs may be mitigated in accordance with the present invention by isolating the anchor bolts from horizontal loads so that they do not need to be sized to resist bending in conjunction with transmitting the horizontal loads between the clamp castings and the concrete foundation at the interface between the pivot edge of the clamp casting and a corresponding pivot surface within the upstream embed. The additional costs of higher gate systems may be further mitigated in accordance with the present invention by providing corrosion protection to the anchor bolt-nut-washer assembly so that a long service life may be assured without resorting to the use of stainless steel. For moderately sized water control gates (up to approximately 3 meters high) of similar configuration. horizontal loads may generally be resisted by anchor bolts of sufficient diameter to resist the resulting bending moments. In the case of water control gates with higher damming heights (5 to 10 meters high, for example), it is more difficult and expensive to provide anchor bolts of sufficient diameter so it is desirable to provide a load path for the usually predominate upstream loads and for the occasional downstream loads separate from the anchor bolts. The provision of a separate load path for horizontal loads not only eliminates undesirable bending moments in the anchor bolts, it also facilitates the use of a flexible or compressible sleeve around the anchor bolts which might otherwise not be able to withstand the resulting lateral compressive loads. A further benefit of the provision of a separate path for horizontal loads is that the relatively thin concrete adjacent to the butt end of the air bladder and hinge flap wedge assemblies is less likely to be broken. Without a sleeve for the anchor bolt, this thin portion of concrete is generally subjected to tensile stresses due to elastic elongation of the anchor bolts in the vertical direction. Without a separate horizontal load path, this portion of concrete may be subjected to tensile loads that cause it to crack and spall off in response to impact loads in the downstream direction to the gate panels. The unique combination of upstream/downstream constraint and a sleeved anchor bolt greatly reduces the likelihood of concrete failure upstream of the air bladder and hinge flap wedges. The concrete in this area may be further protected from cracking or failure by means of an embedded plate or channel, for example, preferably of stainless steel construction. Said embedded plate or channel may serve to align the anchor bolts during concrete placement and is preferably provided with holes to allow air and water escape during concrete placement and to facilitate the addition of concrete as needed to eliminate any voids under said plate or channel.
The provision of a sleeve around the anchor bolts also serves to minimize tensile stresses in the foundation slab in the general vicinity of the anchor bolts. By providing vertical compressive stresses in the concrete, a tri-axial compressive stress state may be established in the concrete as the horizontal tensile loads are assumed by the higher modulus steel reinforcement. The resulting tri-axial stress state in the concrete results in a structurally better foundation while minimization of cracking serves to protect the steel reinforcement from corrosion.
The cost of high strength stainless steel anchor bolts may be unacceptably high in the case of high gate systems. The use of high strength heat-treated alloy steel anchor bolts is facilitated in accordance with the present invention because such non-stainless steel anchor bolts may be readily protected from corrosion.
In accordance with a preferred embodiment of the invention, the clamps are provided with pivotal constraint along their upstream edges so as to limit horizontal movement along the upstream-downstream axis during initial tightening and while in service. Said pivotal constraint provides a load path for horizontal loads due, for example, to rock, ice, or debris impact against the ribs of the lowered gate panel. In accordance with a further aspect of this invention, the range of pivoting motion of the clamp during assembly of the gate system is great enough to allow compression of the rubber components from the relaxed as-placed-onto-spillway state to the fully assembled tightened state which eliminates the need or compression of the assembly by other means, such as a hydraulic excavator bucket. Such range of motion requires extra clearance in the clamp casting to clear the anchor bolt as the clamp casting pivots downward and also requires sufficient clearance between the upstream edge of the upper surface of the clamp casting and the foundation to not cause interference as the clamp is initially placed onto the upstream embed and the uncompressed rubber assembly.
In accordance with a further aspect of this invention a wedge shaped gap may be provided between the upstream edge of the clamp [Does this require a new clamp design with an angled edge?? If so, this should be fully described and claimed. It appears that in
In accordance with a further aspect of this invention, clearance [how much] between the clamps and the anchor bolts, as well as clearance between the clamps and the foundation, allow for periodic re-tightening of the clamps over the life of the rubber components, taking into account compression set and creep of the rubber.
In accordance with a further aspect of this invention, a filler such as silicone RTV caulk may be used to occlude sand and gravel from said wedge shaped gap. [Is this designed to be removed if the clamp is removed for maintenance, etc and then put back in? explain.]
The provision of sleeves around the anchor bolts also serves to minimize tensile stresses in the foundation slab in the general vicinity of the anchor bolts. By providing vertical compressive stresses in the concrete, a tri-axial compressive stress state may be established in the concrete as the horizontal tensile loads are assumed by the higher modulus steel reinforcement. Explain further. The resulting tri-axial stress state in the concrete results in a structurally better foundation while minimization of cracking serves to protect the steel reinforcement from corrosion.
The cost of high strength stainless steel anchor bolts may be unacceptably high in the case of high gate systems. The use of high strength heat treated alloy steel anchor bolts is facilitated in accordance with the present invention because such non-stainless steel anchor bolts may be readily protected from corrosion. The means of corrosion protection in accordance with the present invention may be comprised of one or more of the following elements:
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As can be easily understood from the foregoing, the basic concepts of the present invention may be embodied in a variety of ways. It involves both water control gates or other devices to accomplish the appropriate method. In this application, the inflatable actuation methods are disclosed as part of the results shown to be achieved by the various devices described and as steps which are inherent to utilization. They are simply the natural result of utilizing the devices as intended and described. In addition, while some devices are disclosed, it should be understood that these not only accomplish certain methods but also can be varied in a number of ways. Importantly, as to all of the foregoing, all of these facets should be understood to be encompassed by this disclosure.
The discussion included in this application is intended to serve as a basic description. The reader should be aware that the specific discussion may not explicitly describe all embodiments possible; many alternatives are implicit. It also may not fully explain the generic nature of the invention and may not explicitly show how each feature or element can actually be representative of a broader function or of a great variety of alternative or equivalent elements. Again, these are implicitly included in this disclosure. Where the invention is described in device-oriented terminology, each element of the device implicitly performs a function. Apparatus claims may not only be included for the device described, but also method or process claims may be included to address the functions the invention and each element performs. Neither the description nor the terminology is intended to limit the scope of the claims which are included in this patent application.
This application is the International Phase of and claims priority to U.S. Provisional Application No. 62/026,540 Jul. 18, 2014. Said application is incorporated herein by reference. It is noted that Jul. 18, 2015 was a Saturday, making this patent application due Jul. 20, 2015.
Filing Document | Filing Date | Country | Kind |
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PCT/US15/41214 | 7/20/2015 | WO | 00 |
Number | Date | Country | |
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62026540 | Jul 2014 | US |