Add structural calculation worksheets

Collection of engineering calculation projects (Python + Typst), each with
input, calc script, tests, results, and generated PDF where available.

concentric-footing/results.json

@@ -0,0 +1,84 @@
+{
+  "tool": "concentric_footing",
+  "version": "0.1",
+  "project": "Blavatnik",
+  "prepared_by": "Conemco Engineering",
+  "values": {
+    "Ps_kip": 18.4,
+    "Pu_kip": 26.2,
+    "qa_psf": 2500.0,
+    "q_psf": 2044.444444,
+    "qu_psf": 2911.111111,
+    "Af_ft2": 9.0,
+    "Bf_in": 36.0,
+    "Bf_ft": 3.0,
+    "Df_in": 12.0,
+    "cover_in": 3.0,
+    "d_in": 9.0,
+    "fc_psi": 3000.0,
+    "fy_psi": 60000.0,
+    "fy_ksi": 60.0,
+    "lambda": 1.0,
+    "c_in": 14.0,
+    "bp_in": 6.0,
+    "N": 4,
+    "rebar_size": 4,
+    "db_in": 0.5,
+    "As1_in2": 0.19635,
+    "As_in2": 0.785398,
+    "rho": 0.002424,
+    "rho_min": 0.0018,
+    "L1_in": 2.0,
+    "Vu_one_way_kip": 1.455556,
+    "Vc_one_way_kip": 35.492422,
+    "phiVc_one_way_kip": 26.619316,
+    "bo_in": 92.0,
+    "vc_psi": 219.089023,
+    "Vu_two_way_kip": 15.50571,
+    "Vc_two_way_kip": 181.405711,
+    "phiVn_two_way_kip": 136.054283,
+    "Lc_in": 11.0,
+    "Mu_kipft": 3.669213,
+    "a_in": 0.513332,
+    "beta1": 0.85,
+    "Mn_kipft": 34.334992,
+    "phiMn_kipft": 30.901493,
+    "A1_in2": 36.0,
+    "A2_in2": 1296.0,
+    "sqrt_ratio": 6.0,
+    "Bn_kip": 183.6,
+    "phiBn_kip": 119.34
+  },
+  "checks": {
+    "soil_bearing": {
+      "demand": 2044.444444,
+      "capacity": 2500.0,
+      "ok": true
+    },
+    "one_way_shear": {
+      "demand": 1.455556,
+      "capacity": 26.619316,
+      "ok": true
+    },
+    "two_way_shear": {
+      "demand": 15.50571,
+      "capacity": 136.054283,
+      "ok": true
+    },
+    "flexure": {
+      "demand": 3.669213,
+      "capacity": 30.901493,
+      "ok": true
+    },
+    "minimum_steel": {
+      "demand": 0.0018,
+      "capacity": 0.002424,
+      "ok": true
+    },
+    "bearing": {
+      "demand": 26.2,
+      "capacity": 119.34,
+      "ok": true
+    }
+  }
+}